摘要
分析了含能流的横磁场三比特各向同性XY自旋链的基态纠缠.发现随着外磁场的变化,系统会发生量子相变.以三比特系统为例给出有效哈密顿量的能谱,讨论了体系基态纠缠随λ的变化.当λ<3/3时,在相变点处基态由W态跳跃到非纠缠态,此时自旋链中没有能量流动.当3/3≤λ≤3时,在能级交错点处发生量子相变,体系由非能流相进入能流相,同时基态由W态1跳跃到另一W态5;此时,由于能流的影响,使得基态保持在W态,而不再处于非纠缠态;并且随着λ的增大,系统将在更大范围内处于能流相.当λ>3时,基态波函数表示为5,系统完全处于能流相.
The ground state entanglement in an isotropic three-qubit transverse XY model with energy current is analyzed.A quantum phase transition from a no-energy-current phase to energy-current phase is found when the magnetic field changes.The spectrum of the effective Hamiltonian of the three-qubit system is shown.The ground state entanglement is investigated against λ.When λ<3/3,the ground state changes from a W state to a disentangled state when the magnetic field exceeds the critical point.There is not ener...
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第S1期160-162,共3页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(10447116
10325521
60433050)
关键词
能流
纠缠
量子相变
energy current
entanglement
quantum phase transition
