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arXiv 0911.3201cond-mat.mes-hall
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介观系统低温下的量子相干性:无序效应

Quantum Coherence at Low Temperatures in Mesoscopic Systems: Effect of Disorder

Yasuhiro Niimi, Yannick Baines, Thibaut Capron, Dominique Mailly, Fang-Yuh Lo, Andreas D. Wieck, Tristan Meunier, Laurent Saminadayar, Christopher Bauerle

摘要:

我们研究了由高迁移率GaAs/AlGaAs异质结构制备的准一维线和二维(2D)霍尔条的相位相干时间的无序依赖性。使用一个原始的离子注入技术,我们可以调整由二维电子气感受到的内在的无序,并不断改变系统从半弹道制度的本地化。在扩散状态下,相位相干时间与扩散系数的函数关系符合费米液体理论,没有低温饱和的迹象。令人惊讶的是,在半弹道制度,它变得独立的扩散系数。在强本地化制度,我们发现一个发散的相位相干时间随温度的降低,然而,与弱本地化制度相比,具有较小的指数。

英文摘要:

We study the disorder dependence of the phase coherence time of quasi one-dimensional wires and two-dimensional (2D) Hall bars fabricated from a high mobility GaAs/AlGaAs heterostructure. Using an original ion implantation technique, we can tune the intrinsic disorder felt by the 2D electron gas and continuously vary the system from the semi-ballistic regime to the localized one. In the diffusive regime, the phase coherence time follows a power law as a function of diffusion coefficient as expected in the Fermi liquid theory, without any sign of low temperature saturation. Surprisingly, in the semi-ballistic regime, it becomes independent of the diffusion coefficient. In the strongly localized regime we find a diverging phase coherence time with decreasing temperature, however, with a smaller exponent compared to the weakly localized regime.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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