Spin-splitting and huge positive magnetoresistance in a high-mobility GaAs two-dimensional electron gas
Date Issued
2004
Date
2004
Author(s)
Chiu, Yi-Hsing
DOI
en-US
Abstract
In the thesis, I shall report the transport properties in a high-mobility GaAs two-dimensional electron gas (2DEG). I will introduce them in the following two parts.
1. Spin-splitting in a GaAs two-dimensional electron gas
We have measured the low-temperature electron transport properties in a GaAs/AlGaAs heterostructure. In our system, the enhanced effective g-factor of 9.28 is measured from activation experiments at Landau-level filling factors 1, 3, 5 and 7. We also observe collapse of spin-splitting in which the spin gap approaches 0 at a critical magnetic field of 1.48 T. According to the critical magnetic field , we can expect that the energy caused by the disorder broadening is of 0.79 meV. It is consistent with what we expect from the uncertainty principle.
2. Huge quasi-classical positive magnetoresistance in a high-mobility GaAs two-dimensional electron gas
I shall report observation of huge positive magnetoresistance (PMR) in a high-mobility GaAs 2DEG. The PMR persists up to 80K, demonstrating its quasi-classical origin. We find that where
1. Spin-splitting in a GaAs two-dimensional electron gas
We have measured the low-temperature electron transport properties in a GaAs/AlGaAs heterostructure. In our system, the enhanced effective g-factor of 9.28 is measured from activation experiments at Landau-level filling factors 1, 3, 5 and 7. We also observe collapse of spin-splitting in which the spin gap approaches 0 at a critical magnetic field of 1.48 T. According to the critical magnetic field , we can expect that the energy caused by the disorder broadening is of 0.79 meV. It is consistent with what we expect from the uncertainty principle.
2. Huge quasi-classical positive magnetoresistance in a high-mobility GaAs two-dimensional electron gas
I shall report observation of huge positive magnetoresistance (PMR) in a high-mobility GaAs 2DEG. The PMR persists up to 80K, demonstrating its quasi-classical origin. We find that where
Subjects
二維電子氣
砷化鎵
巨大正磁阻
自旋分裂
two-dimensional electron gas
high-mobility
GaAs
Spin-splitting
huge positive magnetoresistance
Type
thesis
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