美国麻省理工学院William D. Oliver团队研究了各向异性横向噪声引起的量子比特态纯度振荡。相关论文于2025年3月18日发表在《物理评论A》杂志上。

研究组探索了在布洛赫球XY平面中各向异性分布的横向噪声存在下量子比特态纯度的动力学。他们使用沿固定实验室帧轴注入的噪声进行Ramsey实验，并观察到由固有量子比特拉莫尔进动引起的量子比特频率两倍的纯度振荡。

研究组使用低频通量量子比特探索了噪声各向异性、取向和功率谱密度对振荡的依赖性。该结果阐明了横向噪声各向异性对量子比特退相干的影响，可能有助于解开超导量子电路中的电荷和通量噪声。

附：英文原文

Title: Qubit-state purity oscillations from anisotropic transverse noise

Author: David A. Rower, Kotaro Hida, Lamia Ateshian, Helin Zhang, Junyoung An, Max Hays, Sarah E. Muschinske, Christopher M. McNally, Samuel C. Alipour-Fard, Réouven Assouly, Ilan T. Rosen, Bethany M. Niedzielski, Mollie E. Schwartz, Kyle Serniak, Jeffrey A. Grover, William D. Oliver

Issue&Volume: 2025/03/18

Abstract: We explore the dynamics of qubit-state purity in the presence of transverse noise that is anisotropically distributed in the Bloch-sphere XY plane. We perform Ramsey experiments with noise injected along a fixed laboratory-frame axis and observe oscillations in the purity at twice the qubit frequency arising from the intrinsic qubit Larmor precession. We probe the oscillation dependence on the noise anisotropy, orientation, and power spectral density, using a low-frequency fluxonium qubit. Our results elucidate the impact of transverse noise anisotropy on qubit decoherence and may be useful for disentangling charge and flux noise in superconducting quantum circuits.

DOI: 10.1103/PhysRevA.111.032420

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.032420