两体相互作用费米系统在自旋轨道耦合和塞曼场中的基态转变

在超冷费米系统中实现人造规范势的突破,吸引了许多新问题的研究,展现了许多新奇的物理现象.本文研究了在环阱中,具有自旋轨道耦合和塞曼作用的两体相互作用费米模型.通过平面波展开的方法,解析求解了两体费米系统的本征能态.系统的总动量为守恒量,可以在不同总动量空间中研究能谱.研究发现:随着塞曼相互作用增大,在不同总动量空间,两体费米系统的本征能量均逐渐降低,系统基态从总动量为零空间转变到有限值空间.从吸引到排斥相互作用,无塞曼相互作用时,基态总动量始终为零,有塞曼相互作用时,基态总动量从零转变为有限值.通过单粒子和基态动量分布研究,本文直观地揭示了由塞曼能级劈裂引起的基态转变.

Ground energy level transition for two-body interacting Fermionic system with spin-orbit coupling and Zeeman interaction

Experimental realization of artificial gauge field has made it possible to simulate important models with electromagnetic field or spin-orbit interaction in condensed matter physics,which opens a new avenue to engineer novel quantum states and phenomena.The spin-orbit coupled system reveals many significant phenomena in condensed matter physics,such as quantum spin Hall effect,topological insulator and topological superconductor.The combined effect of Zeeman interaction and spin-orbit coupling leads to a nontrivial topological phase.The analytic solution of few-body system provides an in-depth insight into the physical phenomena,which has been studied extensively.Through the analytic study of two-body physics,we show new quantum phenomena for various gauge field parameters.We investigate the two-body interacting fermionic gas with spin-orbit coupling and Zeeman interaction in a ring trap.Through the plane wave expansion method,two-body fermionic system is solved analytically.In the absence of Zeeman interaction,the total momentum of the ground state is zero.With the increase of Zeeman interaction,an energy level crossing occurs between the lowest energy levels for different total momentum spaces and the ground state changes from zero total momentum space to non-zero total momentum space.Considering the Zeeman interaction,the total momentum of the ground state changes from zero to finite value.The single particle analysis shows that the ground energy level transition is induced by Zeeman energy level splitting.The momentum distributions of the ground state are given to provide an intuitive physical picture.This work can be further extended to the exploration of the heteroatom system,lattice system and higher spin system.