马约拉纳四元组器件中$X$和$Z$环测量的不同寿命
Distinct Lifetimes for $X$ and $Z$ Loop Measurements in a Majorana Tetron Device
浏览论文内容
中文总结 AI 辅助
本研究在超导体-半导体异质结中实现马约拉纳四元组量子比特器件，通过双环干涉测量发现X、Z测量的宇称翻转寿命和分配误差存在显著差异，为拓扑量子比特的噪声机制研究提供了实验依据。
中文摘要 AI 辅助
我们展示了超导体-半导体异质结中四元组量子比特器件的硬件实现与测量。该器件结构包含两条平行的超导纳米线（调至拓扑相时可支持四个马约拉纳零模（MZMs））以及一条平凡超导脊线。通过将超导结构与一系列量子点相连，形成了两个不同的读出干涉仪。我们对两个环的费米子宇称进行了单次干涉测量，旨在实现四元组的Pauli-$X$和$Z$测量。重复单次测量得到了两个差异极大的时间尺度：在$X$和$Z$测量环中观测到的宇称翻转时间分别为$τ_X = 14.5\boldsymbol{±} 0.3 \boldsymbol{μs}$和$τ_Z = 12.4\boldsymbol{±} 0.4\boldsymbol{ms}$，我们将其分别归因于线内宇称翻转和外部准粒子中毒。我们估计，基于$X$和$Z$测量的操作的分配误差分别为$\boldsymbol{\rm err}^X_a=16\%$和$\boldsymbol{\rm err}^Z_a=0.5\%$。
英文摘要
We present a hardware realization and measurements of a tetron qubit device in a superconductor-semiconductor heterostructure. The device architecture contains two parallel superconducting nanowires, which support four Majorana zero modes (MZMs) when tuned into the topological phase, and a trivial superconducting backbone. Two distinct readout interferometers are formed by connecting the superconducting structure to a series of quantum dots. We perform single-shot interferometric measurements of the fermion parity for the two loops, designed to implement Pauli-$X$ and $Z$ measurements of the tetron. Performing repeated single-shot measurements yields two widely separated time scales $τ_X = 14.5\pm 0.3 \, \mathrm{μs}$ and $τ_Z = 12.4\pm 0.4\, \mathrm{ms}$ for parity switches observed in the $X$ and $Z$ measurement loops, which we attribute to intra-wire parity switches and external quasiparticle poisoning, respectively. We estimate assignment errors of $\mathrm{err}^X_a=16\%$ and $\mathrm{err}^Z_a=0.5\%$ for $X$ and $Z$ measurement-based operations, respectively.
