Microwave Counting Statistics of Quantum Electronic Systems

*符合计数技术将被用来探测由位相相干导体和参数调制的非线性超导量子腔发射的微波光子的时间关联和全计数统计。微波光子计数元件为大面积约瑟夫森结。当结被适当偏置时，单个微波光子的吸收诱导向电压状态的转变，从而产生大的且易于测量的经典信号。在介观噪声的背景下，微波符合计数将提供相位相干导体发射的微波辐射的全部统计数据。微波光子统计与电子计数统计直接相关，电子计数统计是十多年来理论和实验研究的热点。此外，噪声的多光子相关器将为量子点接触、隧道结和扩散金属纳米线等介观样品提供电子-电子关联和特征能量尺度的窗口。在电路量子电动力学(CQED)的背景下，微波光子计数将作为强耦合区量子电动力学的严格探测器，提供由非线性超导量子腔发射的微波光子的时间关联。在参数调制腔中发射的光子的关联将作为动力学Casimir效应引起的量子辐射的探针。这个实验理论课程为参与的学生提供了丰富的教育机会。非技术摘要要完全描述一个电子设备，人们不仅必须测量通过该设备的平均电流，还必须测量该电流的波动或“噪声”。在大尺寸电阻中，电流是由多个独立的电子贡献的，电流的起伏按熟悉的钟形曲线分布。然而，对于超小型或介观电子设备，电荷传输受量子力学定律支配，电子之间或电子与环境之间的强烈相互作用可以在涨落上留下微妙的特征。在这种情况下，电子噪声可以被用来作为一个强大的探测器，来探测支配运输的潜在物理机制。本程序致力于研究这些介观导体中的噪声和涨落统计，其中输运涉及单个或少数电子的运动，其中量子效应和电荷载流子的强相互作用起着关键作用。这些实验将使用一种新开发的超导探测器，它对介观导体发射的单个微波光子很敏感。这个项目将加深我们对量子体系中电子传输的基本理解。这种理解对于评估新型电子设备的性能至关重要，因为设备规模变得越来越小，以至于量子现象不能再被忽视。在该计划过程中开发的探测技术可能会导致从量子信息科学到天体物理等各种应用的测量方面的进步。该项目将涉及研究生研究人员的广泛参与，并为实验者和理论家提供丰富的教育机会。

****Technical Abstract****Coincidence counting techniques will be employed to probe the temporal correlations and full counting statistics of microwave photons emitted by phase coherent conductors and parametrically modulated, nonlinear superconducting quantum cavities. The microwave photon counter element is a large-area Josephson junction. When the junction is appropriately biased, the absorption of a single microwave photon induces a transition to the voltage state, resulting in a large and easily measured classical signal. In the context of mesoscopic noise, microwave coincidence counting will provide access to the full statistics of the microwave radiation emitted by phase coherent conductors. The microwave photon statistics are directly related to the electron counting statistics, a subject of intense theoretical and experimental interest for a more than a decade. Moreover, multi-photon correlators of the noise will provide a window on electron-electron correlations and characteristic energy scales in mesoscopic samples such as quantum point contacts, tunnel junctions, and diffusive metallic nanowires. In the context of circuit quantum electrodynamics (cQED), microwave photon counting will provide access to temporal correlations of microwave photons emitted by nonlinear superconducting quantum cavities as a rigorous probe of QED in the strong coupling regime. Correlations of emitted photons in parametrically modulated cavities will serve as a probe of the quantum radiation due to the dynamical Casimir effect. This experiment-theory program is rich in educational opportunities for participating students.Non-Technical Abstract****To fully characterize an electronic device, one must measure not only the average current through the device, but also the fluctuations or "noise" of that current. In a large scale electrical resistor, many independent electrons contribute to the current and the fluctuations are distributed according to the familiar bell curve. For an ultrasmall or mesoscopic electronic device, however, charge transport is governed by the laws of quantum mechanics, and strong interactions between electrons or between electrons and their environment can imprint subtle signatures on the fluctuations. In this case, electronic noise can be used as a powerful probe of the underlying physical mechanisms that govern transport. This program is devoted to a study of noise and fluctuation statistics in these mesoscopic conductors, where transport involves the motion of single or few electrons and where quantum effects and strong interactions of the charge carriers play a critical role. The experiments will employ a newly developed superconducting detector that is sensitive to single microwave photons emitted by the mesoscopic conductors. This program will deepen our basic understanding of electronic transport in the quantum regime. This understanding will be essential to evaluate the performance of novel electronic devices as device scales become ever smaller, to the point where quantum phenomena can no longer be ignored. Detection technology developed during the course of this program could lead to advances in measurement for a variety of applications ranging from quantum information science to astrophysics. This program will involve the extensive participation of graduate researchers, and is rich in educational opportunities for both experimenters and theorists.