This paper proposes scalable schemes to generate the Greenberger-Horne-Zeilinger (GHZ) state and the cluster state with atomic ensembles via the dipole blockade mechanism on an atom chip, where the qubit is not carrie...This paper proposes scalable schemes to generate the Greenberger-Horne-Zeilinger (GHZ) state and the cluster state with atomic ensembles via the dipole blockade mechanism on an atom chip, where the qubit is not carried by a single atom but an atomic ensemble. In the protocols, multiqubit entangled states are determinately prepared. Needlessness for single-photon source further decreases the complexity of the experiment. Based on the present laboratory technique, the schemes may be realized. The achieved results reveal a prospect for large-scale quantum communication and quantum computation.展开更多
Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse...Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse. In particular, a class of W states that can be used for perfect teleportation and superdense coding is generated by only one step. Compared with the previous schemes, cavity decay is largely suppressed because the cavity is only virtually excited and always in the vacuum state and the atomic spontaneous emission is strongly restrained due to a large atom-field detuning.展开更多
<Abstract>We propose schemes to prepare n-atom Greenberger-Horne-Zeilinger (GHZ) state via two-sided cavities interacting with single-photon pulses,and achieve quantum state transfer (QST) from one atom to anoth...<Abstract>We propose schemes to prepare n-atom Greenberger-Horne-Zeilinger (GHZ) state via two-sided cavities interacting with single-photon pulses,and achieve quantum state transfer (QST) from one atom to another atom. Entanglement particle pair and the control of coupling between qubits are of no need in the QST process.Some practical quantum noises only decrease the success probabilities of the schemes but have no influence on the fidelity of prepared state.In addition,the success probabilities of our schemes are close to unity in the ideal case.展开更多
This paper presents a direct implementation scheme of the non-local multi-qubit controlled phase gate by using optical fibres and adiabatic passage. The smaller operation number for implementing the multi-qubit contro...This paper presents a direct implementation scheme of the non-local multi-qubit controlled phase gate by using optical fibres and adiabatic passage. The smaller operation number for implementing the multi-qubit controlled phase gate and needlessness for addressing individually save physical resource and lower the difficulties of experiment. Mean-while, the scheme is immune from some decoherence effects such as the atomic spontaneous emission and fibre loss. In principle, it is scalable.展开更多
This paper proposes a scalable scheme to generate n-atom GHZ states and cluster states by using the basic building block, i.e., a weak coherent optical pulse |α> being reflected successively from a single-atom cav...This paper proposes a scalable scheme to generate n-atom GHZ states and cluster states by using the basic building block, i.e., a weak coherent optical pulse |α> being reflected successively from a single-atom cavity. In the schemes, coherent state of light is used instead of single photon source, homodyne measurement on coherent light is done instead of single photon detection, and no need for individually addressing keeps the schemes easy to implement from the experimental point of view. The successful probabilities of our protocols approach unity in the ideal case.展开更多
<正> A system comprising of Lambda-type three-level atoms and the two-mode cavity field is considered in thispaper.Under the adiabatical approximation and the large detuning condition,the effective Hamiltonian o...<正> A system comprising of Lambda-type three-level atoms and the two-mode cavity field is considered in thispaper.Under the adiabatical approximation and the large detuning condition,the effective Hamiltonian of the systemin the interaction picture can be given out.If the two identical three-level atoms pass through the cavity in turn,theentangled state atoms can be generated.When the interaction time is taken to an appropriate value,the maximallyentangled states are created.At the same time,the dynamic behaviors of the system are studied in detail.展开更多
NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical propertie...NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical properties of the films are researched in detail.The NiZnO films could retain a basic wurtzite structure when the Ni content is less than 0.18.As Ni content increases,crystal quality degradation could be observed in the x-ray diffraction patterns and a clear red shift of the absorption edge can be observed in the transmittance spectrum.Furthermore,the donor defects in the NiZnO film can be compensated for effectively by increasing the Ni content.The change of Ni content has an important effect on the properties of NiZnO films.展开更多
This paper proposes a scheme for the implementation of 1 → 3 optimal phase-covariant quantum cloning with trapped ions.In the present protocol,the required time for the whole procedure is short due to the resonant in...This paper proposes a scheme for the implementation of 1 → 3 optimal phase-covariant quantum cloning with trapped ions.In the present protocol,the required time for the whole procedure is short due to the resonant interaction,which is important in view of decoherence.Furthermore,the scheme is feasible based on current technologies.展开更多
The influence of oxygen vacancy on the magnetism of Co-doped ZnO has been investigated by the first-principles calculations.It is suggested that oxygen vacancy and its location play crucial roles on the magnetic prope...The influence of oxygen vacancy on the magnetism of Co-doped ZnO has been investigated by the first-principles calculations.It is suggested that oxygen vacancy and its location play crucial roles on the magnetic properties of Co-doped ZnO.The exchange coupling mechanism should account for the magnetism in Co-doped ZnO with oxygen vacancy and the oxygen vacancy is likely to be close to the Co atom.The oxygen vacancy (doping electrons) might be available for carrier mediation but is localized with a certain length and can strengthen the ferromagnetic exchange interaction between Co atoms.展开更多
This paper proposes schemes for generating multiple-photon and multiple-atom cluster states, respectively. The schemes are based on the cavity input-output process and atomic or photonic states measurement, and the su...This paper proposes schemes for generating multiple-photon and multiple-atom cluster states, respectively. The schemes are based on the cavity input-output process and atomic or photonic states measurement, and the successful probabilities approach unity in the ideal case. The numerical simulations show that the produced multiple-particle cluster states have high fidelity even if the Lamb-Dicke condition is not satisfied. Some practical imperfections, such as atomic spontaneous emission and output coupling inefficiency, only decrease the success probability but exert no influence on the fidelity of generated multiple-particle cluster states. From the experimental point of view, smaller operation number and lack of need for individual addressing keeps the schemes easy to implement. These schemes may offer a promising approach to the generation of a large-scale cluster state.展开更多
This paper proposes a scheme to teleport an arbitrary mixture of diagonal states of multiqutrit via classical correlation and classical communication.To teleport an arbitrary mixture of diagonal states of N qutrits,N ...This paper proposes a scheme to teleport an arbitrary mixture of diagonal states of multiqutrit via classical correlation and classical communication.To teleport an arbitrary mixture of diagonal states of N qutrits,N classically correlated pairs of two qutrits are used as channel.The sender (Alice) makes Fourier transform and conditional gate (i.e.,XOR (3) gate) on her qutrits and does measurement in appropriate computation bases.Then she sends N ctrits to the receiver (Bob).Based on the received information,Bob performs the corresponding unitary transformation on his qutrits and obtains the teleported state.Teleportation of an arbitrary mixture of diagonal states of multiqudit is also discussed.展开更多
Based on the input-output relation of the cavity and the Faraday Rotation mechanism, we propose ascheme for generating the n-atom Creenberger-Horne-Zeilinger state. In the scheme, the n-atom trapped respectively inn s...Based on the input-output relation of the cavity and the Faraday Rotation mechanism, we propose ascheme for generating the n-atom Creenberger-Horne-Zeilinger state. In the scheme, the n-atom trapped respectively inn spatially separate cavities would be entangled with the photons going through the atom-cavity system. The successfulprobabilities of our protocol approach unity in the ideal case. What is more, no requirement for separately addressingfurther lowers experimental difficulties.展开更多
We propose schemes to generate an n-coherent-pulse GHZ state and a cluster state via the interaction between n coherent pulses and a two-sided cavity.In these schemes,a strong coupling condition is not needed,which ma...We propose schemes to generate an n-coherent-pulse GHZ state and a cluster state via the interaction between n coherent pulses and a two-sided cavity.In these schemes,a strong coupling condition is not needed,which makes the protocols possibly able to be implemented based on the current experiment technology.展开更多
基金Project supported by the National Natural Science Foundation （Grant No 10574022）, and the Funds of the Natural Science of Fujian Province, China （Grant No Z0512006）.
基金supported by the National Natural Science Foundation of China (Grant Nos.60878059,10947147,60677044,and 10574022)the Natural Science Foundation of Fujian Province of China (Grant No.2007J0002)
文摘This paper proposes scalable schemes to generate the Greenberger-Horne-Zeilinger (GHZ) state and the cluster state with atomic ensembles via the dipole blockade mechanism on an atom chip, where the qubit is not carried by a single atom but an atomic ensemble. In the protocols, multiqubit entangled states are determinately prepared. Needlessness for single-photon source further decreases the complexity of the experiment. Based on the present laboratory technique, the schemes may be realized. The achieved results reveal a prospect for large-scale quantum communication and quantum computation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60878059, 10947147, 10574022, and 10704010)the Natural Science Foundation of Fujian Province of China (Grant Nos. 2007J0002 and 2010J01002)
文摘Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse. In particular, a class of W states that can be used for perfect teleportation and superdense coding is generated by only one step. Compared with the previous schemes, cavity decay is largely suppressed because the cavity is only virtually excited and always in the vacuum state and the atomic spontaneous emission is strongly restrained due to a large atom-field detuning.
基金supported by National Natural Science Foundation of China under Grant No.10574022the Natural Science Foundation of Fujian Province of China under Grant Nos.A0410016 and 2006J0230Funds of Education Committee of Fujian Province under Grant No.JB05334
文摘<Abstract>We propose schemes to prepare n-atom Greenberger-Horne-Zeilinger (GHZ) state via two-sided cavities interacting with single-photon pulses,and achieve quantum state transfer (QST) from one atom to another atom. Entanglement particle pair and the control of coupling between qubits are of no need in the QST process.Some practical quantum noises only decrease the success probabilities of the schemes but have no influence on the fidelity of prepared state.In addition,the success probabilities of our schemes are close to unity in the ideal case.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574022)Natural Science Foundation of Fujian Province of China (Grant Nos 2007J0002 and 2006J0230)Foundation for Universities in Fujian Province (Grant No 2007F5041)
文摘This paper presents a direct implementation scheme of the non-local multi-qubit controlled phase gate by using optical fibres and adiabatic passage. The smaller operation number for implementing the multi-qubit controlled phase gate and needlessness for addressing individually save physical resource and lower the difficulties of experiment. Mean-while, the scheme is immune from some decoherence effects such as the atomic spontaneous emission and fibre loss. In principle, it is scalable.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574022)the Natural Science Foundation of Fujian Province of China (Grant Nos 2007J0002 and 2006J0230)the Foundation for Universities in Fujian Province (Grant No 2007F5041)
文摘This paper proposes a scalable scheme to generate n-atom GHZ states and cluster states by using the basic building block, i.e., a weak coherent optical pulse |α> being reflected successively from a single-atom cavity. In the schemes, coherent state of light is used instead of single photon source, homodyne measurement on coherent light is done instead of single photon detection, and no need for individually addressing keeps the schemes easy to implement from the experimental point of view. The successful probabilities of our protocols approach unity in the ideal case.
基金The project supported by the National Fundamental Research Program of China under Grant No. 2001CB309300, National Natural Science Foundation of China under Grant No. 10204020, and the Innovation Funds of the Chinese Academy of Sciences
文摘<正> A system comprising of Lambda-type three-level atoms and the two-mode cavity field is considered in thispaper.Under the adiabatical approximation and the large detuning condition,the effective Hamiltonian of the systemin the interaction picture can be given out.If the two identical three-level atoms pass through the cavity in turn,theentangled state atoms can be generated.When the interaction time is taken to an appropriate value,the maximallyentangled states are created.At the same time,the dynamic behaviors of the system are studied in detail.
基金by the National Basic Research Program of China under Grant No 2011CB30200001the National Natural Science Foundation of China under Grant Nos 61006006,60877020,60976010 and 61076045the Science and Technology Development Project in Jilin Province(No 20100170).
文摘NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical properties of the films are researched in detail.The NiZnO films could retain a basic wurtzite structure when the Ni content is less than 0.18.As Ni content increases,crystal quality degradation could be observed in the x-ray diffraction patterns and a clear red shift of the absorption edge can be observed in the transmittance spectrum.Furthermore,the donor defects in the NiZnO film can be compensated for effectively by increasing the Ni content.The change of Ni content has an important effect on the properties of NiZnO films.
基金Project supported by the National Natural Science Foundation of China(Grant Nos10574022 and 10575022)the Funds of the Natural Science of Fujian Province,China(Grant Nos Z0512006 and A0210014)
文摘This paper proposes a scheme for the implementation of 1 → 3 optimal phase-covariant quantum cloning with trapped ions.In the present protocol,the required time for the whole procedure is short due to the resonant interaction,which is important in view of decoherence.Furthermore,the scheme is feasible based on current technologies.
基金supported by the National Key Project for Basic Research of China (Grant No. 2005CB623605)the Fund of National Engineering Research Center for Optoelectronic Crystalline Materials (Grant No. 2005DC105003)the National Natural Science Foundation of China (Grant No. 60876069)
文摘The influence of oxygen vacancy on the magnetism of Co-doped ZnO has been investigated by the first-principles calculations.It is suggested that oxygen vacancy and its location play crucial roles on the magnetic properties of Co-doped ZnO.The exchange coupling mechanism should account for the magnetism in Co-doped ZnO with oxygen vacancy and the oxygen vacancy is likely to be close to the Co atom.The oxygen vacancy (doping electrons) might be available for carrier mediation but is localized with a certain length and can strengthen the ferromagnetic exchange interaction between Co atoms.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574022）, and the Funds of the Natural Science of Fujian Province, China （Grant No Z0512006）.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574022）, and the Funds of the Natural Science of Fujian Province, China （Grant Nos Z0512006 and A0210014）.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574022)the Natural Science Foundation of Fujian Province of China (Grant Nos 2007J0002 and 2006J0230)Funds of Education Committee of Fujian Province of China (Grant No JB05334)
文摘This paper proposes schemes for generating multiple-photon and multiple-atom cluster states, respectively. The schemes are based on the cavity input-output process and atomic or photonic states measurement, and the successful probabilities approach unity in the ideal case. The numerical simulations show that the produced multiple-particle cluster states have high fidelity even if the Lamb-Dicke condition is not satisfied. Some practical imperfections, such as atomic spontaneous emission and output coupling inefficiency, only decrease the success probability but exert no influence on the fidelity of generated multiple-particle cluster states. From the experimental point of view, smaller operation number and lack of need for individual addressing keeps the schemes easy to implement. These schemes may offer a promising approach to the generation of a large-scale cluster state.
基金Project supported by the National Natural Science Foundation of China(Grant No10574022)the Natural Science Foundation of Fujian Province of China(Grant Nos2006J0230 and A0410016)Funds of Education Committee of Fujian Province,China(Grant No JB05334)
文摘This paper proposes a scheme to teleport an arbitrary mixture of diagonal states of multiqutrit via classical correlation and classical communication.To teleport an arbitrary mixture of diagonal states of N qutrits,N classically correlated pairs of two qutrits are used as channel.The sender (Alice) makes Fourier transform and conditional gate (i.e.,XOR (3) gate) on her qutrits and does measurement in appropriate computation bases.Then she sends N ctrits to the receiver (Bob).Based on the received information,Bob performs the corresponding unitary transformation on his qutrits and obtains the teleported state.Teleportation of an arbitrary mixture of diagonal states of multiqudit is also discussed.
基金Supported by Natural Science Foundation of Fujian Province of China under Grant Nos. 2007J0197 and 2007J0002Funds of Education Committee of Fujian Province under Grant No. JB05336
文摘Based on the input-output relation of the cavity and the Faraday Rotation mechanism, we propose ascheme for generating the n-atom Creenberger-Horne-Zeilinger state. In the scheme, the n-atom trapped respectively inn spatially separate cavities would be entangled with the photons going through the atom-cavity system. The successfulprobabilities of our protocol approach unity in the ideal case. What is more, no requirement for separately addressingfurther lowers experimental difficulties.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10574022 and 60878059, the Natural Science Foundation of Fujian Province under Grant No 2007J0002, and the Foundation for Universities in Fujian Province under Grant No 2007F5041.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60878059,60677044,and 10574022)the Natural Science Foundation of Fujian Province of China (Grant No. 2007J0002)
文摘We propose schemes to generate an n-coherent-pulse GHZ state and a cluster state via the interaction between n coherent pulses and a two-sided cavity.In these schemes,a strong coupling condition is not needed,which makes the protocols possibly able to be implemented based on the current experiment technology.
