超导体-半导体异质结构中马约拉纳束缚态的腔调控
Cavity-control of Majorana bound states in superconductor-semiconductor heterostructures
- CPHT, CNRS, École polytechnique, Institut Polytechnique de Paris（法国高等研究中心，法国国家科学研究中心，巴黎综合理工学院，巴黎理工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究从理论上分析了与单模光子腔耦合的超导体-半导体混合平台，发现腔耦合可调控马约拉纳束缚态的相边界，在光-物质耦合强度足够时可抑制超导配对并驱动系统进入无隙相。
AI中文摘要：
我们从理论上研究了一种混合超导体-半导体平台，该平台包含与单模光子腔耦合的马约拉纳束缚态。从嵌入光子腔的、与体s波超导体耦合的一维纳米线出发，我们推导了该平台的有效光-物质哈密顿量。假设光子矢量势沿纳米线与超导体之间的隧穿方向排列，我们发现腔耦合仅出现在有效超导配对项中。通过不同方法求解耦合电子-光子哈密顿量，包括零光子或大量光子情况下的精确对角化、高频展开和平均场退耦，我们发现，与未耦合情况相比，拓扑平凡相之间的相边界移至更小的塞曼能值。在对应大量光子的半经典区域，腔嵌入对相图的影响最强。在所有情况下，我们发现，当光-物质耦合强度较大时，有效超导配对会被抑制，使系统进入无隙相。我们证明，即使较小的光-物质耦合强度，也能使系统在与未耦合平台相比更小的塞曼能值下进入拓扑相。
英文摘要：
We theoretically study a hybrid superconductor-semiconductor platform hosting Majorana bound states coupled to a single mode photonic cavity. Starting with a one-dimensional wire coupled to a bulk $s$-wave superconductor embedded in a photonic cavity, we derive an effective light-matter Hamiltonian for such a platform. Assuming that the photonic vector potential is aligned along the tunneling between a wire and a superconductor, we find that the cavity coupling enters only in the effective superconducting pairing term. By solving the coupled electron-photon Hamiltonian using different approaches, such as exact diagonalization in case of zero or large number of photons, high-frequency expansion, and mean-field decoupling, we find that the phase boundary between the topological trivial phases is shifted to smaller values of the Zeeman energy compared to the uncoupled case. Cavity embedding has the strongest effect on the phase diagram in the semiclassical regime, corresponding to a large number of photons. In all cases, we find that at large values of the light-matter coupling strength the effective superconducting pairing is suppressed, driving the system into the gapless phase. We demonstrate that even small light-matter coupling strength allows for entering the topological phase at values of the Zeeman energy compared to the uncoupled platform.
