Coherence oscillations in dephasing by non-Gaussian shot noise
Coherence oscillations in dephasing by non-Gaussian shot noise
复制标题
非高斯散粒噪声相干振荡
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
F. Marquardt
中科院分区：
文献类型：
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作者：
I. Neder;F. Marquardt
发展了一维电子通道散粒噪声引起的退相的非微扰处理方法。它被应用于两个系统：电荷量子比特和电子马赫-曾德尔干涉仪(MZI)，这两个系统都与作为探测器的相邻分割电子通道相互作用。我们发现可见度(干涉对比度)可以显示作为探测器电压和相互作用时间的函数的振荡。这是散粒噪声的非高斯性的独特结果，并且仅发生在强耦合区域，当单个电子贡献的相位超过π时。由此得到的公式重现了最近在(I Neder等人2006年预印本Cond-MAT/0610634)中报告的令人惊讶的实验观测结果，并对早些时候在大偏置电压下观察到的类似能见度振荡给出了一般解释。我们详细地探索了作为耦合强度、电压和时间的函数的完整的振荡模式，这可能在未来的实验中观察到。
A non-perturbative treatment is developed for the dephasing produced by the shot noise of a one-dimensional electron channel. It is applied to two systems: a charge qubit and the electronic Mach–Zehnder interferometer (MZI), both of them interacting with an adjacent partitioned electronic channel acting as a detector. We find that the visibility (interference contrast) can display oscillations as a function of detector voltage and interaction time. This is a unique consequence of the non-Gaussian properties of the shot noise, and only occurs in the strong coupling regime, when the phase contributed by a single electron exceeds π. The resulting formula reproduces the recent surprising experimental observations reported in (I Neder et al 2006 Preprint cond-mat/0610634), and indicates a general explanation for similar visibility oscillations observed earlier in the MZI at large bias voltage. We explore in detail the full pattern of oscillations as a function of coupling strength, voltage and time, which might be observable in future experiments.