基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自...基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自发形成的T相滑移型堆垛层错(tSSF);在3Rβ-In_(2)Se_(3)中只观察到一种能量较高的滑移型层错;2H和3Rβ-In_(2)Se_(3)以界面连续过渡的方式发生相分离。本文还构建9种β-In_(2)Se_(3)潜在的堆垛层错构型,并计算了相应的堆垛层错能并从能量角度分析了堆垛层错的成因。最后,指出建立分类术语描述类van der Waals层状材料堆垛层错的必要性。展开更多
Superconducting wire-networks are paradigms to study Cooper pairing issues,vortex dynamics and arrangements.Recently,emergent low-dimensional crystalline superconductors were reported in the minimal-disorder limit,pro...Superconducting wire-networks are paradigms to study Cooper pairing issues,vortex dynamics and arrangements.Recently,emergent low-dimensional crystalline superconductors were reported in the minimal-disorder limit,providing novel platforms to reveal vortices-related physics.Study on superconducting loops with high-crystallinity is thus currently demanded.Here,we report fabrication and transport measurement of finite square-network based on two-dimensional crystalline superconductor Mo_(2)C.We observe oscillations in the resistance as a function of the magnetic flux through the loops.Resistance dips at both matching field and fractional fillings are revealed.Temperature and current evolutions are carried out in magnetoresistance to study vortex dynamics.The amplitude of oscillation is enhanced due to the interaction between thermally activated vortices and the currents induced in the loops.The driving current reduces the effective activation energy for vortex,giving rise to stronger vortex interaction.Moreover,by the thermally activated vortex creep model,we derive the effective potential barrier for vortex dissipation,which shows well-defined correspondence with structures in magnetoresistance.Our work shows that low-dimensional crystalline superconducting network based on Mo_(2)C possesses pronounced potential in studying the modulation of vortex arrangements and dynamics,paving the way for further investigations on crystalline superconducting network with various configurations.展开更多
Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation o...Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation of SS,which is limited to 60 mV per decade at room temperature.Herein,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize subthermionic SS in MOSFETs.Through high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport potential.This guides us to screen 192 candidates from the 2D material database comprising 1608 systems.Additionally,the physical relationship between the sub-thermionic transport performances and electronic structures is further revealed,which enables us to predict 15 systems with promising device performances for low-power applications with supply voltage below 0.5 V.This work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimental exploration of intrinsic steep-slope MOSFETs.展开更多
文摘基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自发形成的T相滑移型堆垛层错(tSSF);在3Rβ-In_(2)Se_(3)中只观察到一种能量较高的滑移型层错;2H和3Rβ-In_(2)Se_(3)以界面连续过渡的方式发生相分离。本文还构建9种β-In_(2)Se_(3)潜在的堆垛层错构型,并计算了相应的堆垛层错能并从能量角度分析了堆垛层错的成因。最后,指出建立分类术语描述类van der Waals层状材料堆垛层错的必要性。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974026,11774005,and 51802314)the National Key Research and Development Program of China(Grant No.2017YFA0303304)+1 种基金Science Foundation of Jihua Laboratory(Grant No.2021B0301030003-03)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000)。
文摘Superconducting wire-networks are paradigms to study Cooper pairing issues,vortex dynamics and arrangements.Recently,emergent low-dimensional crystalline superconductors were reported in the minimal-disorder limit,providing novel platforms to reveal vortices-related physics.Study on superconducting loops with high-crystallinity is thus currently demanded.Here,we report fabrication and transport measurement of finite square-network based on two-dimensional crystalline superconductor Mo_(2)C.We observe oscillations in the resistance as a function of the magnetic flux through the loops.Resistance dips at both matching field and fractional fillings are revealed.Temperature and current evolutions are carried out in magnetoresistance to study vortex dynamics.The amplitude of oscillation is enhanced due to the interaction between thermally activated vortices and the currents induced in the loops.The driving current reduces the effective activation energy for vortex,giving rise to stronger vortex interaction.Moreover,by the thermally activated vortex creep model,we derive the effective potential barrier for vortex dissipation,which shows well-defined correspondence with structures in magnetoresistance.Our work shows that low-dimensional crystalline superconducting network based on Mo_(2)C possesses pronounced potential in studying the modulation of vortex arrangements and dynamics,paving the way for further investigations on crystalline superconducting network with various configurations.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_0428)the Training Program of the Major Research Plan of the National Natural Science Foundation of China(91964103)+3 种基金the Natural Science Foundation of Jiangsu Province(BK20180071)the Fundamental Research Funds for the Central Universities(30919011109)sponsored by Qing Lan Project of Jiangsu Province,and the Six Talent Peaks Project of Jiangsu Province(XCL-035)Research Grant Council of Hong Kong(CRS_PolyU502/22).
文摘Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation of SS,which is limited to 60 mV per decade at room temperature.Herein,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize subthermionic SS in MOSFETs.Through high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport potential.This guides us to screen 192 candidates from the 2D material database comprising 1608 systems.Additionally,the physical relationship between the sub-thermionic transport performances and electronic structures is further revealed,which enables us to predict 15 systems with promising device performances for low-power applications with supply voltage below 0.5 V.This work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimental exploration of intrinsic steep-slope MOSFETs.
