AI 中文总结
该研究提出基于量子点-马约拉纳干涉仪的拓扑超导整流器，利用阿哈罗诺夫-玻姆干涉调控电流方向，引入相关因子区分拓扑与平凡整流，为高性能拓扑超导二极管提供可行方案。
AI 中文摘要
我们提出并从理论上研究了一种基于量子点-马约拉纳干涉仪的拓扑超导整流器。由穿过干涉仪环路的磁通量控制的阿哈罗诺夫-玻姆相位，可调节平凡的2π周期量子点通道与拓扑的4π周期马约拉纳通道之间的量子干涉。在非整数通量下，这种干涉会产生持续电流背景I_off，该背景将电流-相位关系转变为单极 regime，其中超电流严格沿单一方向流动。我们引入符号单极性因子η_u，其中|η_u|>0.5定义了单极 regime，并建立了它与传统二极管效率η的定量关系。单极性被证明对量子点能级、自旋极化和马约拉纳杂化的变化具有鲁棒性，会因更强的马约拉纳耦合和拉什巴自旋-轨道相互作用而增强，且在实际温度和准粒子中毒下仍持续存在。我们进一步提出了拓扑二极管品质因子Z_TD，其由η_u的傅里叶谱定义，非零值为4π周期马约拉纳通道提供了与模型无关的特征，并区分了拓扑与平凡的整流机制。我们的发现确立了量子点-马约拉纳干涉仪是通往高性能拓扑超导二极管的有前途途径，其具有可通过标准直流输运测量获取的清晰实验特征。
英文摘要
We propose and theoretically investigate a topological superconducting rectifier based on a quantum-dot--Majorana interferometer. The Aharonov-Bohm phase, controlled by a magnetic flux threading the interferometer loop, tunes the quantum interference between a trivial $2π$-periodic quantum-dot channel and a topological $4π$-periodic Majorana channel. At non-integer flux, this interference generates a persistent current background $I_{\rm off}$ that shifts the current-phase relation into a unipolar regime, in which the supercurrent flows strictly in one direction. We introduce a signed unipolarity factor $η_u$, with $|η_u|>0.5$ defining the unipolar regime, and establish its quantitative relationship to the conventional diode efficiency $η$. The unipolarity proves robust against variations of the quantum-dot level, spin polarization, and Majorana hybridization, is enhanced by stronger Majorana coupling and Rashba spin-orbit interaction, and persists at realistic temperatures and under quasiparticle poisoning. We further propose a topological diode figure of merit $\mathcal{Z}_{\rm TD}$, defined from the Fourier spectrum of $η_u$, whose nonzero value provides a model-independent signature of the $4π$-periodic Majorana channel and distinguishes topological from trivial rectification mechanisms. Our findings establish the quantum-dot--Majorana interferometer as a promising route toward high-performance topological superconducting diodes with clear experimental signatures accessible via standard dc transport measurements.
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