Thermal Coherence in Heisenberg Spin Chains

Ping Xu, Yi-Hai Hu, Xi-Wen Hou

Jiang Xue-Fan, Xing Ding-Yu, Chen Hong

We present a method which combines a thermal coherent state approach with a self-consistent quantum theory to investigate the spin-1/2 dimerized antiferromagnetic Heisenberg chain. It is found that both excitation gaps between the ground state and two lowest excited modes, the triplet one-magnon excitation and the singlet two-magnon bound state decrease monotonically with increasing temperature. Our results are consistent with those obtained from the other approximations.

Oleg A. Starykh, Anders W. Sandvik, Rajiv R. P. Singh

江学范, 陈鸿

We present a method which combines a thermal coherent state approach with a self-consistent quantum theory to investigate the spin-1/2 dimerized antiferromagnetic Heisenberg chain.It is found that both excitation gaps between the ground state and two lowest excited modes,the triplet one-magnon excitation and the singlet two-magnon bound state decrease monotonically with increasing temperature.Our results are consitent with those obtained from the other approximations.

Zhe Yang, Ming Gao, Wei Qin

In this paper, we propose and analyze an efficient high-dimensional quantum state transfer (QST) scheme through an XXZ-Heisenberg spin chain in an inhomogeneous magnetic field. By the use of a combination of coherent quantum coupling and free spin wave approximation, pure unitary evolution results in a perfect high-dimensional swap operation between two remote quantum registers mediated by a uniform quantum data bus and the feasibility is confirmed by numerical simulations. Also, we observe that either the strong z-directional coupling or high quantum spin number can partly suppress the thermal excitations and protect quantum information from the thermal noises when the quantum data bus is in the thermal equilibrium state.

T. Schneider, E. Stoll