葡京娱乐场在线赌场

报告题目：Thermodynamics and quantum criticality of weakly coupled Heisenberg-Ising chains

 

报告时间：2020年5月13日 下午 14：00-16：00

 

报告地点：腾讯会议直播

报告摘要：In this talk I will present our recent progress on the phase diagram and related quantum phase transitions in Heisenberg chains with Ising anisotropic interchain couplings. By using large-scale quantum Monte Carlo simulations, we find the Ising anisotropy of the interchain coupling can significantly enhance longitudinal spin correlations and therefore stabilize an incommensurate longitudinal spin density wave at finite magnetic field. Further increasing the field, the ground state changes to a canted antiferromagnetic phase and the magnetization eventually saturates above a quantum critical point which is shown to fall into the (3+2)D XY universality class. The calculated NMR relaxation rate 1/T_1 suggests that over a broad temperature regime the low-energy excitations of the system can be well described by a Tomonaga-Luttinger liquid. The implication of our results for the spin chain compound YbAlO3 is then discussed.

 

报告人简介：俞榕，中国人民大学物理系教授。2007年获得美国南加州大学博士学位，后在田纳西大学、莱斯大学做博士后。2013年回到中国人民大学物理系工作。近年来专注于铁基超导、量子磁性等方向的理论研究，迄今已发表学术论文90余篇。