Using High-Frequency Surface-Acoustic-Wave to Probe Magnetotransport property of Semiconductor Two-Dimensional Electron System
碩士 === 國立中興大學 === 物理學系 === 90 === We report the conductivity variations of two-dimensional electron systems (2DESs) confined in semiconductor heterostructures in low-temperature (~0.4K) and high-magnetic-field environments by using high-frequency surface acoustic waves (SAWs) generated by an inter d...
Main Author: | |
---|---|
Other Authors: | |
Format: | Others |
Language: | zh-TW |
Published: |
2002
|
Online Access: | http://ndltd.ncl.edu.tw/handle/13045184024452405297 |
Summary: | 碩士 === 國立中興大學 === 物理學系 === 90 === We report the conductivity variations of two-dimensional electron systems (2DESs) confined in semiconductor heterostructures in low-temperature (~0.4K) and high-magnetic-field environments by using high-frequency surface acoustic waves (SAWs) generated by an inter digital transducer (IDT) on a piezoelectric substrate (GaAs or LiNO3). The variations of SAW velocity and attenuation due to the conductivity change near the surface are detected by a phase-lock loop and a power detector respectively. We use pulse-modulated microwave signal and gated-averaging technique to reduce the heating and noise.
|
---|