Electron spin qubits are a promising platform for quantum computation. Environmental noise impedes coherent operations by limiting the qubit relaxation (T₁) and dephasing (T_ϕ) times. There are multiple sources of such noise, which makes it important to devise experimental techniques that can detect the spatial locations of these sources and determine the type of source. In this paper, we propose that anisotropy in T₁ and T_ϕ with respect to the direction of the applied magnetic field can reveal much about these aspects of the noise. We investigate the anisotropy patterns of charge noise, evanescent-wave Johnson noise, and hyperfine noise in hypothetical devices. It is necessary to have a rather well-characterized sample to get the maximum benefit from this technique. The general anisotropy patterns are elucidated. We calculate the expected anisotropy for a particular model of a Si/SiGe quantum dot device.

电子自旋量子比特是一个很有前途的量子计算平台。环境噪声通过限制量子位弛豫 ( T ₁ ) 和移相 ( T _φ ) 时间来阻碍相干操作。这种噪声有多种来源，因此设计能够检测这些噪声源的空间位置并确定源类型的实验技术非常重要。在本文中，我们提出T ₁和T _{φ的各向异性}关于所施加磁场的方向可以揭示噪声的这些方面。我们研究了假设器件中电荷噪声、渐逝波约翰逊噪声和超精细噪声的各向异性模式。为了从这项技术中获得最大收益，有必要拥有一个相当明确的样本。阐明了一般的各向异性模式。我们计算了特定型号的 Si/SiGe 量子点器件的预期各向异性。