Quantum magneto-transport in two-dimensional GaAs electron gases and SiGe hole gases |
| |
| Institution: | 1. Department of Physics, National Taiwan University, Taipei 106, Taiwan;2. Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK;3. Semiconductor Nanofabrication Facilities, School of Physics, University of New South Wales, Sydney 2052, Australia;4. Telecommunication Basic Research Laboratory, ETRI, Yusong PO Box 106, Taejon 305-600, South Korea;5. Materials Evaluation Centre, Korea Research Institute of Standards and Sciences (KRISS), PO Box 102, Taejon 305-600, South Korea;1. International Joint Laboratory for Quantum Functional Materials of Henan, School of Physics and Engineering, Zhengzhou University, Zhengzhou, 450001, China;2. Department of Physics and Research Institute for National Sciences, Hanyang University, 17 Haengdang-Dong, Seongdong-Ku, Seoul, 133-791, Republic of Korea;1. IFP Énergies Nouvelles, 1-4 av. de Bois Préau, F-92852 Rueil-Malmaison, France;2. Center for Economics and Management, IFP School, 228-232 av. Napoléon Bonaparte, F-92852 Rueil-Malmaison, France;3. Department of Economics, City, University of London, Northampton Square, London EC1V 0HB, UK;4. Climate Economics Chair, Palais Brongniart, 28 place de la Bourse, F-75002 Paris, France;5. Chair “The Economics of Natural Gas”, Paris, France;1. Center for Vein Restoration, Greenbelt, Md;2. Center for Vascular Medicine, Greenbelt, Md;1. Information Physics Research Center, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China;2. School of Physics, Southeast University, Nanjing, 210096, China;1. Department of Physics, Jining University, 273155 Qufu, Shandong, China;2. Department of Physics, Qufu Normal University, 273165 Qufu, Shandong, China;3. Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, SP, Brazil;4. Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil |
| |
| Abstract: | We have measured the low-temperature transport properties of two-dimensional (2D) GaAs electron gases and 2D SiGe hole gases. Our experimental results fall into three categories. (i) Collapse of spin-splitting and an enhanced Landé g-factor at Landau level filling factors both ν=3 and ν=1 in a 2D GaAs electron gas are observed. Our experimental results show direct evidence that the effective disorder is stronger at ν=1 than that at ν=3 over approximately the same perpendicular magnetic field range. (ii) We present evidence for spin-polarisation of a dilute 2D GaAs electron gas. The Lande g-factor of the system is estimated to be 1.66. This enhanced g value is ascribed to electron–electron interactions at ultra low carrier density limit. (iii) In a high-quality SiGe hole gas, there is a temperature-independent point in the magnetoresistivity ρxx and ρxy which is ascribed to experimental evidence for a quantum phase transition between ν=3 and ν=5. We also present a study on the temperature(T)-driven flow lines in our system. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
