Tuning the electron transport properties of a one-dimensional constriction using hydrostatic pressure
Tuning the electron transport properties of a one-dimensional constriction using hydrostatic pressure
复制标题
使用静水压力调节一维收缩的电子传输特性
DOI：
10.1103/physrevb.65.233316
复制
发表时间：
2002
影响因子：
3.7
通讯作者：
M. Pepper
中科院分区：
文献类型：
--
作者：
R. Wirtz;R. Newbury;J. Nicholls;W. Tribe;M. Simmons;M. Pepper
利用静水压力和光照研究了在$\mathrm{GaAs}/{\mathrm{Al}}_{x}{\mathrm{Ga}} {1\ensuremath{-}x}\mathrm{As}$界面形成的深二维电子气体（2DEG）中电子通过干净的一维压缩的传输。在${2e}^{2}/h的整数倍下，观察到多达20个量子化电导步骤，以及一个明显的额外步骤（“0.7结构”），大约$0.7\ifmmode\times\else\texttimes\fi{}{2e}^{2}/h。在压力和光照的双重作用下，2DEG中的电子密度从$2.14\ifmmode\倍\else\texttimes\fi{}{15}{\mathrm{m}}^{\ensuremath{-}2}$降低到$0.6\ifmmode\倍\else\texttimes\fi{}{10}^{15}{\mathrm{m}}^{\ensuremath{-}2}，并观察到“0.7结构”的电导向自旋分离值${e}^{2}/h$移动。密度测量结果与通过求解异质结构的Schr\ odinger-Poisson方程得到的二维电子密度作为压力函数的计算结果进行了比较。高压下持续的光导效应也有逆转，这是无法解释的。
Hydrostatic pressure and illumination have been used to investigate electron transport through a clean one-dimensional constriction in a deep two-dimensional electron gas (2DEG) formed at a $\mathrm{GaAs}/{\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ interface. Up to 20 quantized conductance steps were observed at integer multiples of ${2e}^{2}/h,$ as well as a clear additional step (the ``0.7 structure'') at approximately $0.7\ifmmode\times\else\texttimes\fi{}{2e}^{2}/h.$ Using both pressure and illumination the electron density in the 2DEG was reduced from $2.14\ifmmode\times\else\texttimes\fi{}{10}^{15}{\mathrm{m}}^{\ensuremath{-}2}$ to $0.6\ifmmode\times\else\texttimes\fi{}{10}^{15}{\mathrm{m}}^{\ensuremath{-}2},$ and a shift in the conductance of the ``0.7 structure'' towards the spin-split value of ${e}^{2}/h$ was observed. The density measurements are compared to calculations of the 2D electron density as a function of pressure, obtained by solving the Schr\"odinger-Poisson equation for the heterostructure. There is also a reversal of the persistent photoconductivity effect at high pressures that cannot be accounted for.