Crépel Valentin, Guerci Daniele, Cano Jennifer, Pixley J H, Millis Andrew
Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA.
Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
Phys Rev Lett. 2023 Aug 4;131(5):056001. doi: 10.1103/PhysRevLett.131.056001.
We show that topological superconductivity may emerge upon doping of transition metal dichalcogenide heterobilayers above an integer-filling magnetic state of the topmost valence moiré band. The effective attraction between charge carriers is generated by an electric p-wave Feshbach resonance arising from interlayer excitonic physics and has a tunable strength, which may be large. Together with the low moiré carrier densities reachable by gating, this robust attraction enables access to the long-sought p-wave BEC-BCS transition. The topological protection arises from an emergent time reversal symmetry occurring when the magnetic order and long wavelength magnetic fluctuations do not couple different valleys. The resulting topological superconductor features helical Majorana edge modes, leading to half-integer quantized spin-thermal Hall conductivity and to charge currents induced by circularly polarized light or other time-reversal symmetry-breaking fields.
我们表明，在过渡金属二硫族化物异质双层中，当在最顶层价莫尔带的整数填充磁态之上进行掺杂时，可能会出现拓扑超导性。电荷载流子之间的有效吸引力是由层间激子物理产生的电偶极波费什巴赫共振所产生的，并且具有可调节的强度，该强度可能很大。再加上通过门控可实现的低莫尔载流子密度，这种强大的吸引力使得能够实现长期以来寻求的偶极波玻色 - 爱因斯坦凝聚 - 巴丁 - 库珀 - 施里弗转变。当磁序和长波长磁涨落不耦合不同能谷时，会出现一种涌现的时间反演对称性，从而产生拓扑保护。由此产生的拓扑超导体具有螺旋马约拉纳边缘模式，导致半整数量子化的自旋 - 热霍尔电导率以及由圆偏振光或其他破坏时间反演对称性的场诱导的电荷电流。
