Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields...Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields,can give rise to directional dichroism of the electrical transport phenomena via the magnetochiral anisotropy.In this study,we investigate the nonreciprocal magneto-transport in microdevices of NbGe_(2),a superconductor with structural chirality.A giant nonreciprocal signal from vortex motions is observed during the superconducting transition,with the ratio of nonreciprocal resistance to the normal resistanceγreaching 6×10^(5)T^(-1)·A^(-1).Interestingly,the intensity can be adjusted and even sign-reversed by varying the current,the temperature,and the crystalline orientation.Our findings illustrate intricate vortex dynamics and offer ways of manipulation on the rectification effect in superconductors with structural chirality.展开更多
A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads t...A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption.展开更多
Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,...Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,it is extremely difficult to achieve nonreciprocity of heat transfer.This review presents the recent developments in thermal nonreciprocity and explores the fundamental theories,which underpin the design of nonreciprocal thermal metamaterials,i.e.,the Onsager reciprocity theorem.Next,three methods for achieving nonreciprocal metamaterials in the thermal field are elucidated,namely,nonlinearity,spatiotemporal modulation,and angular momentum bias,and the applications of nonreciprocal thermal metamaterials are outlined.We also discuss nonreciprocal thermal radiation.Moreover,the potential applications of nonreciprocity to other Laplacian physical fields are discussed.Finally,the prospects for advancing nonreciprocal thermal metamaterials are highlighted,including developments in device design and manufacturing techniques and machine learning-assisted material design.展开更多
We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorpti...We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorption.Periodical defects in the MGPCs work as filters.Absorption bands(ABs)for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively,and they prove to share no overlaps in the studied frequency range.Givenω=2.0138 THz,for the positive propagation,the ABs in the high-frequency range are localized in the interval between 0.66ωand 0.88ω.In the angular range,the ABs for the TE and TM waves reach 60°and 51°,separately.For the negative propagation,the ABs in the low-frequency range are localized in the interval between 0.13ωand 0.3ω.The AB s extend to 60°for the TE waves and 80.4°for the TM waves.There also exists a narrow frequency band in a lower frequency range.The relevant factors,which include the external temperature,the magnetic fields applied to the YIGF,the refractive index of the impedance matching layer,and the defect thickness,are adjusted to investigate the effects on the ABs.All the numerical simulations are based on the transfer matrix method.This work provides an approach to designs of isolators and so on.展开更多
Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded p...Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.展开更多
We investigate the electromagnetic properties of a four-level dense atomic gas medium with Doppler effect.It is shown that the relative permittivity and relative permeability of the medium can be negative simultaneous...We investigate the electromagnetic properties of a four-level dense atomic gas medium with Doppler effect.It is shown that the relative permittivity and relative permeability of the medium can be negative simultaneously with low absorption in the same detuning interval on account of electromagnetically induced transparency.Furthermore,with the suitable parameters,the nonreciprocal negative refraction can be obtained due to the Doppler effect,and the nonreciprocity frequency band can be regulated by adjusting the temperature,the intensity of the control field and the atomic density in this hot atomic medium.展开更多
We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon t...We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon transmission,the nonreciprocity is induced by the effects of chiral coupling and atomic dissipation in the weak coupling region.It vanishes in the strong coupling regime when the effect of atomic dissipation becomes ignorable.In the case of two-photon transmission,there exist two ways of going through the emitter:independently as plane waves and formation of bound state.Besides the nonreciprocal behavior of plane waves,the bound state that differs in two directions also alters transmission probabilities.In addition,the second-order correlation of transmitted photons depends on the interference between plane wave and bound state.The destructive interference leads to the strong antibunching in the weak coupling region,while the effective formation of bound state leads to the strong bunching in the intermediate coupling region.However,the negligible interactions for left-propagating photons hardly change the statistics of the input coherent state.展开更多
We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical mo...We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical modes are coupled by Coulomb interaction, and two optical modes are coupled to one of mechanical modes by radiation pressure. We numerically evaluate the transmission probability of the probe field to obtain the optimum optical nonreciprocal response parameters. Also, we show that the optical nonreciprocal response is caused by the quantum interference between the optomechanical couplings and the linearly coupled interaction that breaks the time-reversal symmetry.展开更多
In this work,the three-dimensional(3 D)propagation behaviors in the nonlinear phononic crystal and elastic wave metamaterial with initial stresses are investigated.The analytical solutions of the fundamental wave and ...In this work,the three-dimensional(3 D)propagation behaviors in the nonlinear phononic crystal and elastic wave metamaterial with initial stresses are investigated.The analytical solutions of the fundamental wave and second harmonic with the quasilongitudinal(qP)and quasi-shear(qS_(1) and qS_(2))modes are derived.Based on the transfer and stiffness matrices,band gaps with initial stresses are obtained by the Bloch theorem.The transmission coefficients are calculated to support the band gap property,and the tunability of the nonreciprocal transmission by the initial stress is discussed.This work is expected to provide a way to tune the nonreciprocal transmission with vector characteristics.展开更多
We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity,where the optomechanical cavity mode couples with the mechanical mode via...We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity,where the optomechanical cavity mode couples with the mechanical mode via radiation-pressure interaction,and simultaneously couples with the auxiliary cavity mode via nonreciprocal coupling.We study the entanglement between the mechanical oscillator and the cavity modes when the two cavities are reciprocally or non-reciprocally coupled.The logarithmic negativity E_(n)^((1))(E_(n)^((2)))is adopted to describe the entanglement degree between the mechanical mode and the optomechanical cavity mode(the auxiliary cavity mode).We find that both E_(n)^((1))and E_(n)^((2))have maximum values in the case of reciprocal coupling.By using nonreciprocal coupling,E_(n)^((1))and E_(n)^((2))can exceed those maximum values,and a wider detuning region where the entanglement exists can be obtained.Moreover,the entanglement robustness with respect to the environment temperature is also effectively enhanced.展开更多
In this paper, the nonreciprocal properties of a novel kind of 1D magnetized plasma photonic crystals(MPPCs) with the Fibonacci sequence are investigated. The isolation of the proposed 1D MPPCs is also used to analyze...In this paper, the nonreciprocal properties of a novel kind of 1D magnetized plasma photonic crystals(MPPCs) with the Fibonacci sequence are investigated. The isolation of the proposed 1D MPPCs is also used to analyze the nonreciprocal properties. Compared to the conventional 1D MPPCs with periodic structure, the nonreciprocal performance can be significantly improved.The effects of several parameters of the proposed 1D MPPCs on the nonreciprocal properties are studied by the transfer matrix method, which includes the incident angle, order of the Fibonacci sequence, plasma frequency, plasma cyclotron frequency and plasma filling factor. The obtained results show that the nonreciprocal propagation properties can be improved by increasing the values of the plasma cyclotron frequency and incident angle, but they will worsen by blindly increasing the order of the Fibonacci sequence, plasma frequency and filling factor of plasma.The peaks of transmittance also are obviously reduced. In addition, the value of isolation will increase with increasing the incident angle, order of Fibonacci sequence, plasma frequency and plasma filling factor. However, when the plasma cyclotron frequency is increased, the value of isolation will be increased at lower frequencies, but is almost unchanged at higher frequencies.展开更多
We investigate the non-reciprocal transmission properties of a three-layer structure filled with magneto–optical medium and normal medium. Based on the transfer matrix method, we deduce the total transmission coeffic...We investigate the non-reciprocal transmission properties of a three-layer structure filled with magneto–optical medium and normal medium. Based on the transfer matrix method, we deduce the total transmission coefficient for a one-dimensional(1 D) structure with anisotropic mediums. When two-side layers with magneto–optical medium loaded in opposite external magnetic field, the time-reversal symmetry of transmission properties will be broken. Our numerical results show that the non-reciprocal transmission properties are influenced by external magnetic fields, incident angle, and thickness of the normal medium layer. Since the non-reciprocal properties can be easily realized and adjusted by the simple structure, such a design has potential applications in integrated circulators and isolators.展开更多
The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the re...The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.展开更多
A nonlocal circulator protocol is proposed in a hybrid optomechanical system.By analogy with quantum communication,using the input-output relationship,we establish the quantum channel between two optical modes with lo...A nonlocal circulator protocol is proposed in a hybrid optomechanical system.By analogy with quantum communication,using the input-output relationship,we establish the quantum channel between two optical modes with long-range.The three-body nonlocal interaction between the cavity and the two oscillators is obtained by eliminating the optomechanical cavity mode and verifying the Bell-CHSH inequality of continuous variables.By introducing the phase accumulation between cyclic interactions,the unidirectional transmission of quantum state between the optical mode and two mechanical modes is achieved.The results show that nonreciprocal transmissions are achieved as long as the accumulated phase reaches a certain value.In addition,the effective interaction parameters in our system are amplified,which reduces the difficulty of the implementation of our protocol.Our research can provide potential applications for nonlocal manipulation and transmission control of quantum platforms.展开更多
We present a work of manipulating collective unconventional photon blockade(UCPB)and nonreciprocal UCPB(NUCPB)in a cavity-driven system composed of an asymmetrical single-mode cavity and two interacting identical twol...We present a work of manipulating collective unconventional photon blockade(UCPB)and nonreciprocal UCPB(NUCPB)in a cavity-driven system composed of an asymmetrical single-mode cavity and two interacting identical twolevel atoms(TLAs).When the atoms do not interact directly,the frequency and intensity restrictions of collective UCPB can be specified,and a giant NUCPB exists due to the splitting of optimal atom–cavity coupling strength in proper parameter regime.However,if a weak atom–atom interaction which provides a new and feeble quantum interference pathway to UCPB is taken into account,two restrictions of UCPB are combined complexly,which are rigorous to be matched simultaneously.Due to the push-and-pull effect induced by weak dipole–dipole interaction,the UCPB regime is compressed more or less.NUCPB is improved as a higher contrast is present when the two complex UCPB restrictions are matched,while it is suppressed when the restrictions are mismatched.In general,whether NUCPB is suppressed or promoted depends on its working parameters.Our findings show a prospective access to produce giant quantum nonreciprocity by a couple of weakly interacting atoms.展开更多
We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices ...We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.展开更多
According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic e...According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic energy conversion and management.The introduction of Weyl semimetals and magneto-optical(MO)materials into photonic crystals makes it possible to violate Kirchhoff's law,but most existing work only report the unequal absorptivity and emissivity spectra in a single band,which cannot meet the requirements of most practical applications.Here,we introduce a defect layer into the structure composed of one-dimensional(1D)magnetophotonic crystal and a metal layer,which realizes dual-band nonreciprocal thermal radiation under a 3-T magnetic field with an incident angle of 60°.The realization of dual-band nonreciprocal radiation is mainly due to the Fabry-Perot(FP)resonance occurring in the defect layer and the excitation of Tamm plasmon,which is proved by calculating the magnetic field distribution.In addition,the effects of incident angle and structural parameters on nonreciprocity are also studied.What is more,the number of nonreciprocal bands could be further increased by tuning the defect layer thickness.When the defect layer thickness increases to 18.2μm,tri-band nonreciprocal thermal radiation is realized due to the enhanced number of defect modes in the photonic band gap and the FP resonance occurring in the defect layer.Finally,the effect of defect location on nonreciprocity is also discussed.The present work provides a new way for the design of multi-band or even broad-band nonreciprocal thermal emitters.展开更多
The long-wave infrared band(8–14μm)is essential for several applications,such as infrared detection,radiative cooling,and near-field heat transfer.However,according to Kirchhoff’s law,the intrinsic balance between ...The long-wave infrared band(8–14μm)is essential for several applications,such as infrared detection,radiative cooling,and near-field heat transfer.However,according to Kirchhoff’s law,the intrinsic balance between thermal absorption and emission limits the further improvement of photon energy conversion and thermal management.Thus,breaking Kirchhoff’s balance and achieving nonreciprocal thermal radiation in the long-wave infrared band are necessary.Most existing designs for nonreciprocal thermal emitters rely on grating or photonic crystal structures to achieve nonreciprocal thermal radiation at narrow peaks,which are relatively complex and typically realize bands larger than 14μm.Here,a sandwich structure consisting of an epsilon-nearzero(ENZ)magneto-optical layer(MOL),a dielectric layer(DL),and a metal layer is proposed to achieve a strong nonreciprocal effect in the long-wave infrared band,which is mainly attributed to the strengthening of the asymmetric Berreman mode by the Fabry–Perot cavity.In addition,the impact of the incident angle,DL thickness,and DL refractive index on the nonreciprocal thermal radiation has been investigated.Moreover,by replacing the ENZ MOL with the gradient ENZ MOL,the existence of the DL can further improve the nonreciprocity of the broadband nonreciprocal thermal radiation.The proposed work promotes the development and application of nonreciprocal energy devices.展开更多
A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant ...A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant atom setup is highly desirable.In this study,the nonreciprocal single-photon scattering characteristics of a double-drivenΛ-type three-level giant atom,where one of the transition couples to a 1D waveguide at two separate points,and the other is driven by two coherent driving fields,are investigated.It is found that a frequency-tunable single-photon diode with an ideal contrast ratio can be achieved by properly manipulating the local coupling phases between the giant atom and the waveguide,the accumulation phase between the two waveguide coupling points,the Rabi frequencies and phase difference of the two driven fields.Compared to the previous single driving schemes,on the one hand,the presence of the second driving field can provide more tunable parameters to manipulate the nonreciprocal single-photon scattering behavior.On the other hand,here perfect nonreciprocal transmission for photons with arbitrary frequencies is achievable by tuning the driving phases while the two driving fields keep on turning,which provides an alternative way to control the nonreciprocal single-photon scattering.Furthermore,the results reveal that both the location and width of each optimal nonreciprocal transmission window is also sensitive to the driving detuning,and a single-photon diode with wide or narrow bandwidth can be realized based on demand.These results may be beneficial for designing nonreciprocal single-photon devices based on a double-driven giant atom setup.展开更多
Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensin...Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403603)the National Natural Science Foundation of China(Grant Nos.U2032213,12104461,12374129,and 12304156)+1 种基金Chinese Academy of Sciences(Grant Nos.YSBR-084,and JZHKYPT-2021-08)A portion of this work was supported by the High Magnetic Field Laboratory of Anhui Province.
文摘Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields,can give rise to directional dichroism of the electrical transport phenomena via the magnetochiral anisotropy.In this study,we investigate the nonreciprocal magneto-transport in microdevices of NbGe_(2),a superconductor with structural chirality.A giant nonreciprocal signal from vortex motions is observed during the superconducting transition,with the ratio of nonreciprocal resistance to the normal resistanceγreaching 6×10^(5)T^(-1)·A^(-1).Interestingly,the intensity can be adjusted and even sign-reversed by varying the current,the temperature,and the crystalline orientation.Our findings illustrate intricate vortex dynamics and offer ways of manipulation on the rectification effect in superconductors with structural chirality.
文摘A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption.
基金the National Natural Science Foundation of China(No.52325208)the Fundamental Research Funds for the Central Universities(No.06500174)National Key Research and Development Program of China(No.2022YFB3807401)。
文摘Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,it is extremely difficult to achieve nonreciprocity of heat transfer.This review presents the recent developments in thermal nonreciprocity and explores the fundamental theories,which underpin the design of nonreciprocal thermal metamaterials,i.e.,the Onsager reciprocity theorem.Next,three methods for achieving nonreciprocal metamaterials in the thermal field are elucidated,namely,nonlinearity,spatiotemporal modulation,and angular momentum bias,and the applications of nonreciprocal thermal metamaterials are outlined.We also discuss nonreciprocal thermal radiation.Moreover,the potential applications of nonreciprocity to other Laplacian physical fields are discussed.Finally,the prospects for advancing nonreciprocal thermal metamaterials are highlighted,including developments in device design and manufacturing techniques and machine learning-assisted material design.
基金Project supported by the College Student Innovation Training Program of Nanjing University of Posts and Telecommunicationsthe Jiangsu Agriculture Science and Technology Innovation Fund(JASTIF)(Grant No.CX(21)3187)。
文摘We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorption.Periodical defects in the MGPCs work as filters.Absorption bands(ABs)for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively,and they prove to share no overlaps in the studied frequency range.Givenω=2.0138 THz,for the positive propagation,the ABs in the high-frequency range are localized in the interval between 0.66ωand 0.88ω.In the angular range,the ABs for the TE and TM waves reach 60°and 51°,separately.For the negative propagation,the ABs in the low-frequency range are localized in the interval between 0.13ωand 0.3ω.The AB s extend to 60°for the TE waves and 80.4°for the TM waves.There also exists a narrow frequency band in a lower frequency range.The relevant factors,which include the external temperature,the magnetic fields applied to the YIGF,the refractive index of the impedance matching layer,and the defect thickness,are adjusted to investigate the effects on the ABs.All the numerical simulations are based on the transfer matrix method.This work provides an approach to designs of isolators and so on.
文摘Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.
基金Project supported by the National Natural Science Foundation of China(Grant No.61671279)financial support from Xi’an Key Laboratory of Optical Information Manipulation and Augmentation(OMA)。
文摘We investigate the electromagnetic properties of a four-level dense atomic gas medium with Doppler effect.It is shown that the relative permittivity and relative permeability of the medium can be negative simultaneously with low absorption in the same detuning interval on account of electromagnetically induced transparency.Furthermore,with the suitable parameters,the nonreciprocal negative refraction can be obtained due to the Doppler effect,and the nonreciprocity frequency band can be regulated by adjusting the temperature,the intensity of the control field and the atomic density in this hot atomic medium.
基金supported by the National Natural Science Foundation of China(Grant No.11704045)。
文摘We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon transmission,the nonreciprocity is induced by the effects of chiral coupling and atomic dissipation in the weak coupling region.It vanishes in the strong coupling regime when the effect of atomic dissipation becomes ignorable.In the case of two-photon transmission,there exist two ways of going through the emitter:independently as plane waves and formation of bound state.Besides the nonreciprocal behavior of plane waves,the bound state that differs in two directions also alters transmission probabilities.In addition,the second-order correlation of transmitted photons depends on the interference between plane wave and bound state.The destructive interference leads to the strong antibunching in the weak coupling region,while the effective formation of bound state leads to the strong bunching in the intermediate coupling region.However,the negligible interactions for left-propagating photons hardly change the statistics of the input coherent state.
文摘We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical modes are coupled by Coulomb interaction, and two optical modes are coupled to one of mechanical modes by radiation pressure. We numerically evaluate the transmission probability of the probe field to obtain the optimum optical nonreciprocal response parameters. Also, we show that the optical nonreciprocal response is caused by the quantum interference between the optomechanical couplings and the linearly coupled interaction that breaks the time-reversal symmetry.
基金Project supported by the National Natural Science Foundation of China(Nos.11922209,11991031 and 12021002)。
文摘In this work,the three-dimensional(3 D)propagation behaviors in the nonlinear phononic crystal and elastic wave metamaterial with initial stresses are investigated.The analytical solutions of the fundamental wave and second harmonic with the quasilongitudinal(qP)and quasi-shear(qS_(1) and qS_(2))modes are derived.Based on the transfer and stiffness matrices,band gaps with initial stresses are obtained by the Bloch theorem.The transmission coefficients are calculated to support the band gap property,and the tunability of the nonreciprocal transmission by the initial stress is discussed.This work is expected to provide a way to tune the nonreciprocal transmission with vector characteristics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12047520,61941501,61775062,11574092,61378012,91121023,62071186 and 61771205).
文摘We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity,where the optomechanical cavity mode couples with the mechanical mode via radiation-pressure interaction,and simultaneously couples with the auxiliary cavity mode via nonreciprocal coupling.We study the entanglement between the mechanical oscillator and the cavity modes when the two cavities are reciprocally or non-reciprocally coupled.The logarithmic negativity E_(n)^((1))(E_(n)^((2)))is adopted to describe the entanglement degree between the mechanical mode and the optomechanical cavity mode(the auxiliary cavity mode).We find that both E_(n)^((1))and E_(n)^((2))have maximum values in the case of reciprocal coupling.By using nonreciprocal coupling,E_(n)^((1))and E_(n)^((2))can exceed those maximum values,and a wider detuning region where the entanglement exists can be obtained.Moreover,the entanglement robustness with respect to the environment temperature is also effectively enhanced.
基金funded by the Postdoctoral Foundation of Jiangsu Province (No. 1501016A)the China Postdoctoral Science Foundation (No. 2015M581790)the special grade China Postdoctoral Science Foundation (No. 2016T90455)
文摘In this paper, the nonreciprocal properties of a novel kind of 1D magnetized plasma photonic crystals(MPPCs) with the Fibonacci sequence are investigated. The isolation of the proposed 1D MPPCs is also used to analyze the nonreciprocal properties. Compared to the conventional 1D MPPCs with periodic structure, the nonreciprocal performance can be significantly improved.The effects of several parameters of the proposed 1D MPPCs on the nonreciprocal properties are studied by the transfer matrix method, which includes the incident angle, order of the Fibonacci sequence, plasma frequency, plasma cyclotron frequency and plasma filling factor. The obtained results show that the nonreciprocal propagation properties can be improved by increasing the values of the plasma cyclotron frequency and incident angle, but they will worsen by blindly increasing the order of the Fibonacci sequence, plasma frequency and filling factor of plasma.The peaks of transmittance also are obviously reduced. In addition, the value of isolation will increase with increasing the incident angle, order of Fibonacci sequence, plasma frequency and plasma filling factor. However, when the plasma cyclotron frequency is increased, the value of isolation will be increased at lower frequencies, but is almost unchanged at higher frequencies.
文摘We investigate the non-reciprocal transmission properties of a three-layer structure filled with magneto–optical medium and normal medium. Based on the transfer matrix method, we deduce the total transmission coefficient for a one-dimensional(1 D) structure with anisotropic mediums. When two-side layers with magneto–optical medium loaded in opposite external magnetic field, the time-reversal symmetry of transmission properties will be broken. Our numerical results show that the non-reciprocal transmission properties are influenced by external magnetic fields, incident angle, and thickness of the normal medium layer. Since the non-reciprocal properties can be easily realized and adjusted by the simple structure, such a design has potential applications in integrated circulators and isolators.
基金Supported by the Anhui Provincial Natural Science Foundation under Grant No 1608085MA09the National Natural Science Foundation of China under Grant Nos 11774262,61675006,11474003 and 61472282
文摘The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12061023,12074206,11704026,11704205,11704042,and 11847128)K.C.Wong Magna Fund in Ningbo University,China。
文摘A nonlocal circulator protocol is proposed in a hybrid optomechanical system.By analogy with quantum communication,using the input-output relationship,we establish the quantum channel between two optical modes with long-range.The three-body nonlocal interaction between the cavity and the two oscillators is obtained by eliminating the optomechanical cavity mode and verifying the Bell-CHSH inequality of continuous variables.By introducing the phase accumulation between cyclic interactions,the unidirectional transmission of quantum state between the optical mode and two mechanical modes is achieved.The results show that nonreciprocal transmissions are achieved as long as the accumulated phase reaches a certain value.In addition,the effective interaction parameters in our system are amplified,which reduces the difficulty of the implementation of our protocol.Our research can provide potential applications for nonlocal manipulation and transmission control of quantum platforms.
基金the National Natural Science Foundation of China(Grants Nos.12164022,11864018,and 12174288)the Fundamental Research Funds for the Provincial Universities of Zhejiang Province,China(Grant No.GK199900299012-015)。
文摘We present a work of manipulating collective unconventional photon blockade(UCPB)and nonreciprocal UCPB(NUCPB)in a cavity-driven system composed of an asymmetrical single-mode cavity and two interacting identical twolevel atoms(TLAs).When the atoms do not interact directly,the frequency and intensity restrictions of collective UCPB can be specified,and a giant NUCPB exists due to the splitting of optimal atom–cavity coupling strength in proper parameter regime.However,if a weak atom–atom interaction which provides a new and feeble quantum interference pathway to UCPB is taken into account,two restrictions of UCPB are combined complexly,which are rigorous to be matched simultaneously.Due to the push-and-pull effect induced by weak dipole–dipole interaction,the UCPB regime is compressed more or less.NUCPB is improved as a higher contrast is present when the two complex UCPB restrictions are matched,while it is suppressed when the restrictions are mismatched.In general,whether NUCPB is suppressed or promoted depends on its working parameters.Our findings show a prospective access to produce giant quantum nonreciprocity by a couple of weakly interacting atoms.
基金the LiaoNing Revitalization Talents Program(Grant No.XLYC1907033)the National Natural Science Foundation of China(Grant No.11905027)+1 种基金the Natural Science Foundation of Liaoning province(Grant No.2023-MS-072)Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant Nos.N2209005 and N2205015).
文摘We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.52211540005,52076087)the Open Project Program of Wuhan National Laboratory for Optoelectronics(Grant No.2021WNLOKF004)+1 种基金Wuhan Knowledge Innovation Shuguang Programthe Science and Technology Program of Hubei Province(Grant No.2021BLB176)。
文摘According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic energy conversion and management.The introduction of Weyl semimetals and magneto-optical(MO)materials into photonic crystals makes it possible to violate Kirchhoff's law,but most existing work only report the unequal absorptivity and emissivity spectra in a single band,which cannot meet the requirements of most practical applications.Here,we introduce a defect layer into the structure composed of one-dimensional(1D)magnetophotonic crystal and a metal layer,which realizes dual-band nonreciprocal thermal radiation under a 3-T magnetic field with an incident angle of 60°.The realization of dual-band nonreciprocal radiation is mainly due to the Fabry-Perot(FP)resonance occurring in the defect layer and the excitation of Tamm plasmon,which is proved by calculating the magnetic field distribution.In addition,the effects of incident angle and structural parameters on nonreciprocity are also studied.What is more,the number of nonreciprocal bands could be further increased by tuning the defect layer thickness.When the defect layer thickness increases to 18.2μm,tri-band nonreciprocal thermal radiation is realized due to the enhanced number of defect modes in the photonic band gap and the FP resonance occurring in the defect layer.Finally,the effect of defect location on nonreciprocity is also discussed.The present work provides a new way for the design of multi-band or even broad-band nonreciprocal thermal emitters.
基金supported by the National Natural Science Foundation of China(Grant Nos.52211540005 and 52076087)the Natural Science Foundation of Hubei Province(Grant No.2023AFA072)+1 种基金the Open Project Program of Wuhan National Laboratory for Optoelectronics(Grant No.2021WNLOKF004)Wuhan Knowledge Innovation Shuguang Program,and the Fundamental Research Funds for the Central Universities(Grant No.YCJJ20242102).
文摘The long-wave infrared band(8–14μm)is essential for several applications,such as infrared detection,radiative cooling,and near-field heat transfer.However,according to Kirchhoff’s law,the intrinsic balance between thermal absorption and emission limits the further improvement of photon energy conversion and thermal management.Thus,breaking Kirchhoff’s balance and achieving nonreciprocal thermal radiation in the long-wave infrared band are necessary.Most existing designs for nonreciprocal thermal emitters rely on grating or photonic crystal structures to achieve nonreciprocal thermal radiation at narrow peaks,which are relatively complex and typically realize bands larger than 14μm.Here,a sandwich structure consisting of an epsilon-nearzero(ENZ)magneto-optical layer(MOL),a dielectric layer(DL),and a metal layer is proposed to achieve a strong nonreciprocal effect in the long-wave infrared band,which is mainly attributed to the strengthening of the asymmetric Berreman mode by the Fabry–Perot cavity.In addition,the impact of the incident angle,DL thickness,and DL refractive index on the nonreciprocal thermal radiation has been investigated.Moreover,by replacing the ENZ MOL with the gradient ENZ MOL,the existence of the DL can further improve the nonreciprocity of the broadband nonreciprocal thermal radiation.The proposed work promotes the development and application of nonreciprocal energy devices.
基金supported by the China Postdoctoral Science Foundation (Grant No.2023M732028)the Zhejiang Province Key Laboratory of Quantum Technology and Device (Grant No.20230201)+2 种基金the Zhejiang Provincial Natural Science Foundation of China (Grant No.LY21A040003)the National Key Research and Development Program of China (Grant No.2021YFA1400602)the National Natural Science Foundation of China (Grant Nos.11864018,12164022,12174288 and 12274326)。
文摘A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant atom setup is highly desirable.In this study,the nonreciprocal single-photon scattering characteristics of a double-drivenΛ-type three-level giant atom,where one of the transition couples to a 1D waveguide at two separate points,and the other is driven by two coherent driving fields,are investigated.It is found that a frequency-tunable single-photon diode with an ideal contrast ratio can be achieved by properly manipulating the local coupling phases between the giant atom and the waveguide,the accumulation phase between the two waveguide coupling points,the Rabi frequencies and phase difference of the two driven fields.Compared to the previous single driving schemes,on the one hand,the presence of the second driving field can provide more tunable parameters to manipulate the nonreciprocal single-photon scattering behavior.On the other hand,here perfect nonreciprocal transmission for photons with arbitrary frequencies is achievable by tuning the driving phases while the two driving fields keep on turning,which provides an alternative way to control the nonreciprocal single-photon scattering.Furthermore,the results reveal that both the location and width of each optimal nonreciprocal transmission window is also sensitive to the driving detuning,and a single-photon diode with wide or narrow bandwidth can be realized based on demand.These results may be beneficial for designing nonreciprocal single-photon devices based on a double-driven giant atom setup.
基金supported by the National Natural Science Foundation of China(Grant No.11935006)the Hunan Provincial Major Sci-Tech Program(Grant No.2023ZJ1010)+10 种基金the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC4047)supported by the National Natural Science Foundation of China(Grant Nos.12247105,12175060,and 11935006)XJ-Lab Key Project(Grant No.23XJ02001).Keyu Xia was supported by the National Key R&D Program of China(Grant No.2019YFA0308704)the National Natural Science Foundation of China(Grant No.92365107)the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138)supported by the National Natural Science Foundation of China(Grant No.12205054)the Jiangxi Provincial Education Office Natural Science Fund Project(Grant No.GJJ211437)the Ph.D.Research Foundation(Grant No.BSJJ202122)supported by the National Natural Science Foundation of China(Grant No.12265004)supported by the National Natural Science Foundation of China(Grant No.12205256)the Henan Provincial Science and Technology Research Project(GrantNo.232102221001)。
文摘Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.
