Interaction effects in a one-dimensional constriction
Interaction effects in a one-dimensional constriction
复制标题
DOI：
10.1103/physrevb.58.4846
复制
发表时间：
1998-08-15
影响因子：
3.7
通讯作者：
Ritchie, DA
中科院分区：
文献类型：
--
作者：
Thomas, KJ;Nicholls, JT;Ritchie, DA
我们研究了高质量 GaAs/AlxGa1-xAs 异质结构中由分裂栅极定义的一维 (1D) 收缩的传输特性。除了通常的量子化电导平台之外，平衡电导显示出接近 0.7(2e(2)/h) 的结构，并且巩固了我们之前的工作 [K. J. Thomas 等人，物理学家。莱特牧师。 77, 135 (1996)] 这种 0.7 结构已在多种样品中作为温度、载流子密度、平行面内磁场 B 和源漏电压 V-sd 的函数进行了研究。我们证明0.7结构不是由于传输或共振效应造成的，也不是由于异质结在生长方向上的不对称性引起的。所有 1D 子带均显示高 B 平行的塞曼分裂，并且在宽沟道限制中，g 因子约为 0.4，接近块状 GaAs。随着通道逐渐变窄，我们测量了交换增强的 g 因子。测量结果表明 0.7 结构与自旋相关，并且电子-电子相互作用对于最后几个导电一维子带变得重要。
We have investigated the transport properties of one-dimensional (1D) constrictions defined by split-gates in high quality GaAs/AlxGa1-xAs heterostructures. In addition to the usual quantized conductance plateaus, the equilibrium conductance shows a structure close to 0.7(2e(2)/h), and in consolidating our previous work [K. J. Thomas at al., Phys. Rev. Lett. 77, 135 (1996)] this 0.7 structure has been investigated in a wide range of samples as a function of temperature, carrier density, in-plane magnetic field B-parallel to, and source-drain voltage V-sd. We show that the 0.7 structure is not due to transmission or resonance effects, nor does it arise from the asymmetry of the heterojunction in the growth direction. All the 1D subbands show Zeeman splitting at high B-parallel to and in the wide channel limit the g factor is \g\approximate to 0.4, close to that of bulk GaAs. As the channel is progressively narrowed we measure an exchange-enhanced g factor. The measurements establish that the 0.7 structure is related to spin, and that electron-electron interactions become important for the last few conducting 1D subbands.