费米气体通过量子点接触的输运行为简介INTRODUCTION TO THE TRANSPORT OF FERMI GASES THROUGH QUANTUM POINT CONTACTS
单春园,代晓宇,刘波扬
摘要(Abstract):
输运测量是研究物质状态基本性质的重要工具。其中通过量子点接触(Quantum Point Contact)的输运是介观物理学中一个非常有趣的现象。在无相互作用或弱相互作用费米系统中,电导随门电压的变化呈现出量子化的阶梯状,这一现象揭示了物质的量子特性。近年来,冷原子体系中输运的研究已成为该领域的前沿研究之一冷原子体系具有高度可操控性的特点,也存在许多新奇物态,因此可以在冷原子的输运实验中观测到许多材料物理中无法观测到的新的实验现象。本文将以综述的形式介绍冷原子费米气体通过量子点接触的输运行为的一些前沿实验进展,此外,我们也将介绍处理该体系常用的非平衡场论方法。
关键词(KeyWords): 冷原子;输运行为;量子点接触;非平衡场论
基金项目(Foundation):
作者(Author): 单春园,代晓宇,刘波扬
参考文献(References):
- [1] VAN WEES B J,van HOUTEN H,BEENAKKER C W J.Quantized conductance of point contacts in a two-dimensional electron gas[J].Physical Review Letters,1988,60(9):848-850.
- [2] WHARAM D A,THORNTON T J,NEWBURY R,et al.One-dimensional transport and the quantisation of the ballistic resistance[J].Journal of Physics C:solid state physics,1988,21(8):209.
- [3] LANDAUER R.Spatial variation of currents and fields due to localized scatterers in metallic conduction[J].IBM Journal of Research and Development,1957,1(3):223-231.
- [4] BüTTIKER M,IMRY Y,LANDAUER R,et al.Generalized many-channel conductance formula with application to small rings[J].Physical Review B,1985,31(10):6207.
- [5] KRINNER S,STADLER D,HUSMANN D,et al.Observation of quantized conductance in neutral matter[J].Nature,2015,517(7532):64-67.
- [6] HUSMANN D,UCHINO S,KRINNER S,et al.Connecting strongly correlated superfluids by a quantum point contact[J].Science,2015,350(6267):1498-1501.
- [7] KRINNER S,LEBRAT M,HUSMANN D,et al.Mapping out spin and particle conductances in a quantum point contact[J].Proceedings of the National Academy of Sciences,2016,113(29):8144-8149.
- [8] KANáSZ-NAGY M,GLAZMAN L,ESSLINGER T,et al.Anomalous conductances in an ultracold quantum wire[J].Physical review letters,2016,117(25):255302.
- [9] UCHINO S,UEDA M.Anomalous transport in the superfluid fluctuation regime[J].Physical review letters,2017,118(10):105303.
- [10] LIU B,ZHAI H,ZHANG S.Anomalous conductance of a strongly interacting Fermi gas through a quantum point contact[J].Physical Review A,2017,95(1):013623.
- [11] BRANTUT J P,GRENIER C,MEINEKE J,et al.A thermoelectric heat engine with ultracold atoms[J].Science,2013,342(6159):713-715.
- [12] HAN X,LIU B,HU J .Enhancement of the thermal-transport figure of merit and breakdown of the Wiedemann-Franz law in unitary Fermi gases[J].Physical Review A,2019,100:04360.
- [13] HUSMANN D,LEBRAT M,H?USLER S,et al.Breakdown of the Wiedemann-Franz law in a unitary Fermi gas[J].Proceedings of the National Academy of Sciences,2018,115(34):8563-8568.
- [14] H?USLER S,NAKAJIMA S,LEBRAT M,et al.Scanning gate microscope for cold atomic gases[J].Physical Review Letters,2017,119(3):030403.
- [15] LEBRAT M,H?USLER S,FABRITIUS P,et al.Quantized conductance through a spin-selective atomic point contact[J].Physical review letters,2019,123(19):193605.
- [16] CORMAN L,FABRITIUS P,HUSLER S,et al.Erratum:Quantized conductance through a dissipative atomic point contact[J].Physical review A,2019,100:053605.
- [17] NAZAROV Y V,BLANTER Y M.Quantum transport:introduction to nanoscience[M].United Kingdom:Cambridge university press,2009.
- [18] COHEN M H,FALICOV L M,PHILLIPS J C.Superconductive tunneling[J].Physical Review Letters,1962,8(8):316.
- [19] DUKE C B,LAMBE J.Tunneling in Solids[J].Physics Today,1973,26(6):63-64.
- [20] CUEVAS J C,MARTíN-RODERO A,YEYATI A L.Hamiltonian approach to the transport properties of superconducting quantum point contacts[J].Physical Review B,1996,54(10):7366.
- [21] KELDYSH L V.Diagram technique for nonequilibrium processes[J].soviet physics jetp,1965,20(4):1018-1026.
- [22] ALEX K.Field Theory of Non-Equilibrium Systems[M].United Kingdom:Cambridge University Press,2011.