First- and Second-Order Topological Superconductivity and Temperature-Driven Topological Phase Transitions in the Extended Hubbard Model with Spin-Orbit Coupling
First- and Second-Order Topological Superconductivity and Temperature-Driven Topological Phase Transitions in the Extended Hubbard Model with Spin-Orbit Coupling
复制标题
具有自旋轨道耦合的扩展哈伯德模型中的一阶和二阶拓扑超导性和温度驱动的拓扑相变
DOI：
10.1103/physrevlett.125.017001
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发表时间：
2020
影响因子：
8.6
通讯作者：
Frank Marsiglio
中科院分区：
文献类型：
--
作者：
Majid Kheirkhah;Zhongbo Yan;Yuki Nagai;Frank Marsiglio
自旋-轨道耦合与相互作用的结合导致了物质的许多奇异相。在这封信中，我们研究了零温度和有限温度下平均场能级内具有Rashba和Dresselhaus自旋轨道耦合的二维扩展Hubbard模型的超导配对不稳定性。我们发现，第一和第二阶时间反演对称性破缺拓扑间隙相位可以实现适当的参数和温度制度下，由于存在一个有利的偶宇称波配对，即使在没有外部磁场或内禀磁性。这导致在每个边缘上的手性马约拉纳边缘状态的两个分支或在样品的每个角处的单个零能量马约拉纳角状态。有趣的是，我们还发现，不仅调谐掺杂水平导致这两个不同的拓扑带隙相之间的直接拓扑相变，但也使用温度作为一个高度可控的和可逆的调谐旋钮导致不同的直接温度驱动的拓扑带隙和无带隙的拓扑超导相之间的相变。我们的研究结果提出了新的可能性，在相互作用的自旋轨道耦合系统统一的第一和更高阶的拓扑超导体在一个简单但现实的微观模型。
The combination of spin-orbit coupling with interactions results in many exotic phases of matter. In this Letter, we investigate the superconducting pairing instability of the two-dimensional extended Hubbard model with both Rashba and Dresselhaus spin-orbit coupling within the mean-field level at both zero and finite temperature. We find that both first- and second-order time-reversal symmetry breaking topological gapped phases can be achieved under appropriate parameters and temperature regimes due to the presence of a favored even-parity-wave pairing even in the absence of an external magnetic field or intrinsic magnetism. This results in two branches of chiral Majorana edge states on each edge or a single zero-energy Majorana corner state at each corner of the sample. Interestingly, we also find that not only does tuning the doping level lead to a direct topological phase transition between these two distinct topological gapped phases, but also using the temperature as a highly controllable and reversible tuning knob leads to different direct temperature-driven topological phase transitions between gapped and gapless topological superconducting phases. Our findings suggest new possibilities in interacting spin-orbit coupled systems by unifying both first- and higher-order topological superconductors in a simple but realistic microscopic model.