Quantum Hall based Aharonov-Bohm spectroscopy: electron-electron interaction in non-linear magnetotransport

Aharonov-Bohm谱是研究准粒子在整数和分数量子霍尔区量子统计的有力工具。相关的主要活动特别是由寻找非阿贝尔态驱动的，这可能为拓扑量子信息处理铺平道路。然而，对于这两种量子霍尔效应，仍然缺乏对相互作用如何影响量子态的详细理解。我们将通过进行相位相关的磁输运实验，结合考虑电子-电子相互作用的自洽模型计算来应对这一挑战。我们的重点是非线性，但仍然相位相干制度的边缘通道运输，这超出了现有的努力。实验将在Aharonov-Bohm干涉仪上进行，该干涉仪可以用作量子开关，定义在GaAs基异质结构中的二维电子熔池中。相位相干量子霍尔边缘态作为干涉仪臂。熔池的几何形状和这些边缘状态的性质由施加到顶栅的电压控制。这种场效应技术使我们能够调整限制电位的陡度，从而定义引导各个干涉仪臂的不对称边缘。我们自己以前的研究表明，这种门定义的量子霍尔态的不对称性的强烈影响。我们计划研究相位相干输运性质的量子开关在非线性制度的对称性和其他参数，包括磁场强度，温度，载流子密度和迁移率的函数。我们的研究将为理解相互作用如何影响量子霍尔态提供一个新的水平。

Aharonov-Bohm spectroscopy is a powerful tool to study the quantum statistics of quasi particles in the integer and fractional quantum Hall regimes. Related major activities are in particular driven by the search for non-abelian states which could pave the path towards topological quantum information processing. However, a detailed understanding of how interaction affects the quantum states is still lacking for both quantum Hall effects. We will tackle this challenge by performing phase dependent magneto-transport experiments in conjunction with self consistent model calculations taking into account electron-electron interaction. Our focus is the nonlinear but still phase coherent regime of edge channel transport; this goes beyond existing efforts. The experiments will be conducted on an Aharonov-Bohm interferometer, which can be employed as a quantum switch, defined in a two-dimensional electron puddle in a GaAs based heterostructure. Phase coherent quantum Hall edge states serve as the interferometer arms. The geometry of the puddle and nature of these edge states are controlled by voltages applied to top gates. This field effect technique allows us to tune the steepness of the confinement potential and, thus, define asymmetric edges guiding individual interferometer arms. Our own previous studies demonstrate a strong impact of such gate defined asymmetries on the quantum Hall states. We plan to study phase coherent transport properties of the quantum switch in the nonlinear regime as a function of symmetry and other parameters including magnetic field strength, temperature, carrier density and mobility. Our studies will provide a new level of understanding of how interactions affect the quantum Hall states.