电子非厄米系统中的拓扑自旋图样

Topological spin textures in electronic non-Hermitian systems

Non-Hermitian systems have been discussed mostly in the context of open systems and nonequilibrium.Recent experimental progress is much from optical,cold-atomic,and classical platforms due to the vast tunability and clear identification of observables.However,their counterpart in solid-state electronic systems in equilibrium remains unmasked although highly desired,where a variety of materials are available,calculations are solidly founded,and accurate spectroscopic techniques can be applied.We demonstrate that,in the surface state of a topological insulator with spin-dependent relaxation due to magnetic impurities,highly nontrivial topological soliton spin textures appear in momentum space.Such spin-channel phenomena are delicately related to the type of non-Hermiticity and correctly reveal the most robust non-Hermitian features detectable spectroscopically.Moreover,the distinct topological soliton objects can be deformed to each other,mediated by topological transitions driven by tuning across a critical direction of doped magnetism.These results not only open a solid-state avenue to exotic spin patterns via spin-and angle-resolved photoemission spectroscopy,but also inspire non-Hermitian dissipation engineering of spins in solids.