Experimental test of universal conductance fluctuations by means of wave-chaotic microwave cavities
Experimental test of universal conductance fluctuations by means of wave-chaotic microwave cavities
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DOI：
10.1103/physrevb.74.195326
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发表时间：
2006-11-01
影响因子：
3.7
通讯作者：
Anlage, Steven M.
中科院分区：
文献类型：
--
作者：
Hemmady, Sameer;Hart, James;Anlage, Steven M.
利用与时间无关的薛定谔方程和亥姆霍兹方程的数学等价性，提供了一种利用二维微波腔研究弹道混沌介观系统普遍电导波动的方法。在适当形状的微波腔内，经典混沌射线轨迹的作用类似于在没有热涨落的情况下，通过弹道量子点的非相互作用电子输运的混沌动力学。微波腔通过两个单模端口进行耦合，并采用基于测量的辐射阻抗矩阵的方法消除了端口和腔之间非理想耦合的影响。应用Landauer-Buttiker公式计算了相应介观量子点器件的电导。我们发现实验推导的替代电导的概率密度函数及其均值和方差与browwer和Beenakker的理论预测非常一致。我们还观察到量子失相参数与腔欧姆损耗参数之间存在线性关系。
The mathematical equivalence of the time-independent Schrodinger equation and the Helmholtz equation is exploited to provide a means of studying universal conductance fluctuations in ballistic chaotic mesoscopic systems using a two-dimensional microwave cavity. The classically chaotic ray trajectories within a suitably shaped microwave cavity play a role analogous to that of the chaotic dynamics of noninteracting electron transport through a ballistic quantum dot in the absence of thermal fluctuations. The microwave cavity is coupled through two single-mode ports and the effect of nonideal coupling between the ports and cavity is removed by a previously developed method based on the measured radiation impedance matrix. The Landauer-Buttiker formalism is applied to obtain the conductance of a corresponding mesoscopic quantum-dot device. We find good agreement for the probability density functions of the experimentally derived surrogate conductance, as well as its mean and variance, with the theoretical predictions of Brouwer and Beenakker. We also observe a linear relation between the quantum dephasing parameter and the cavity ohmic loss parameter.