论文标题
固定阵列附近金属物体的磁噪声
Magnetic Noise from Metal Objects near Qubit Arrays
论文作者
论文摘要
所有金属物体都支持由于热效应和量子效应而导致其附近evanescent-Wave Johnson噪声的波动电流。噪音场可以在其附近放置Qubits。它通过$ b（x，t）b（x'，t'）$的平均值及其时间傅立叶变换来量化。我们尤其是针对与皮肤深度相比尺寸较小的物体的形式主义，这是纳米级设备的适当状态。这为任意形状对象的噪声相关函数提供了一个一般且令人惊讶的简单公式。该公式在对象中的诱导电流方面具有明确的物理解释。它也可能是直接数值评估的基础。对于球体，以广义多极扩展为封闭形式给出了解决方案。解决方案图说明了涉及的物理原理。我们举例说明噪声的空间模式如何影响附近Qubits的量子信息处理。该理论意味着，如果将量子系统微型化为缩放$ d $，则将Qubits量表的分解率为$ 1/d $。
All metal objects support fluctuating currents that are responsible for evanescent-wave Johnson noise in their vicinity due both to thermal and quantum effects. The noise fields can decohere qubits in their neighborhood. It is quantified by the average value of $B(x,t)B(x',t')$ and its time Fourier transform. We develop the formalism particularly for objects whose dimensions are small compared with the skin depth, which is the appropriate regime for nanoscale devices. This leads to a general and surprisingly simple formula for the noise correlation function of an object of arbitrary shape. This formula has a clear physical interpretation in terms of induced currents in the object. It can also be the basis for straightforward numerical evaluation. For a sphere, a solution is given in closed form in terms of a generalized multipole expansion. Plots of the solution illustrate the physical principles involved. We give examples of how the spatial pattern of noise can affect quantum information processing in nearby qubits. The theory implies that if the qubit system is miniaturized to a scale $D$, then decoherence rates of qubits scale as $1/D$.
