AI 中文总结
本研究利用菱面石墨烯的低温热霍尔电导直接测量手征超导体的Bogoliubov-de Gennes陈数，验证了拓扑不变量的守恒性，为手征超导的实验表征提供了新方法。
AI 中文摘要
手征超导体沿边缘携带手征马约拉纳模式，且存在单一整数——Bogoliubov-de Gennes陈数，可对这些模式计数。三十年来，候选材料始终未实现该整数的测量，原因是通常采用的磁信号不具备拓扑保护性。菱面石墨烯使这一问题既紧迫又可解答：磁成像可分辨超导相内部可重写的时间反演对称破缺畴，而量子振荡揭示了复杂到无法逐个费口袋重构的正常态。我们表明，低温热霍尔电导可直接返回该整数，无需此类重构。对于带投影配对，它等于动量空间占据区域所包围的配对涡旋缠绕数。将谷内哈密顿量拆分为对称与反对称部分，可分离真实材料的三角翘曲和有限库珀对动量：反对称部分拓扑惰性，对525个参数点的直接陈数计算显示该不变量守恒，且存在一个不等式标记Bogoliubov费表面消除量子化的位置。随后，平台κ_xy/T=(π²k_B²/6h)C_BdG可读出该整数，其符号随成像畴反转，一条写入的畴壁应携带2|C_BdG|个马约拉纳通道，所需测温已能在毫开尔文温度下分辨封装石墨烯中的单个热量子。
英文摘要
A chiral superconductor carries chiral Majorana modes along its edges, and a single integer, the Bogoliubov--de Gennes Chern number, counts them. Thirty years of candidate materials have not yielded a measurement of that integer, because the magnetic signatures usually invoked are not topologically protected. Rhombohedral graphene makes the question both urgent and answerable: magnetic imaging resolves rewritable time-reversal-breaking domains inside the superconducting phase, while quantum oscillations reveal a normal state too intricate to reconstruct pocket by pocket. We show that the low-temperature thermal Hall conductance returns the integer directly, with no such reconstruction. For band-projected pairing it equals the pairing-vortex winding enclosed by the occupied regions of momentum space. Splitting the intravalley Hamiltonian into symmetric and antisymmetric parts isolates the trigonal warping and finite Cooper pair momentum of the real material: the antisymmetric part is topologically inert, direct Chern calculations across $525$ parameter points show the invariant preserved, and one inequality marks where a Bogoliubov Fermi surface removes quantization. The plateau $κ_{xy}/T=(π^2k_B^2/6h)\,C_{\rm BdG}$ then reads out the integer, its sign reverses with the imaged domain, a written domain wall should carry $2|C_{\rm BdG}|$ Majorana channels, and the thermometry required already resolves single thermal quanta in encapsulated graphene at millikelvin temperatures.
Comments27 pages, 8 figures
