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

基于量子霍尔的阿哈罗诺夫-玻姆光谱：非线性磁输运中的电子-电子相互作用

• 批准号: 218453298
• 负责人: Privatdozent Dr. Stefan Ludwig
• 金额: --
• 依托单位: Paul-Drude-Institut für Festkörperelektronik (PDI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/218453298?language=en
• 关键词: Quantum; Hall; based; Aharonov; Bohm

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.

阿哈罗诺夫-玻姆光谱是研究整数和分数量子霍尔体系中准粒子的量子统计的强大工具。相关的主要活动尤其是由对非阿贝尔态的搜索驱动的，这可以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。我们将通过执行相相关磁输运实验并结合考虑电子-电子相互作用的自洽模型计算来应对这一挑战。我们的重点是边缘通道传输的非线性但仍然相位相干的机制；这超出了现有的努力。实验将在阿哈罗诺夫-玻姆干涉仪上进行，该干涉仪可用作量子开关，定义在基于砷化镓的异质结构中的二维电子坑中。相位相干量子霍尔边缘态充当干涉仪臂。水坑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势的陡度，从而定义引导各个干涉仪臂的不对称边缘。我们自己之前的研究证明了这种门定义的不对称性对量子霍尔态的强烈影响。我们计划研究非线性状态下量子开关的相位相干传输特性作为对称性和其他参数（包括磁场强度、温度、载流子密度和迁移率）的函数。我们的研究将为相互作用如何影响量子霍尔态提供新的理解。