双层冰中量子相变研究

A study of quantum phase transition in bilayer ice

针对实验所得的双层冰体系,采用原胞动力学平均场理论,结合连续时间量子蒙特卡罗方法,设计开发了一套模拟双层冰结构的准三维六角晶格系统,研究了强关联相互作用与温度的竞合对系统中金属-莫特绝缘相变的影响,结果表明,通过对体系的态密度、双占据数和费米面的计算,可以看出随着相互作用的增加,氧原子经过的金属-莫特绝缘相变(如T/t=0.2时U_(C)/t=6.5)为二级相变。由于体系受温度影响形成近藤共振峰,氢原子的费米面始终存在尖锐的费米液状峰。以双层冰实验为依据,仿真其发生量子相变的过程,计算结果将为双层冰在强关联方面的研究提供理论参考。

For the experimentally obtained double-layer ice system,a quasi-3D hexagonal lattice system simulating the double-layer ice structure is designed and developed by using the protocell dynamics mean-field theory in combination with the continuous-time quantum Monte Carlo method,and the effect of the strong correlation interactions with the competing temperatures on the metal-Mott insulating phase transition in the system is investigated.The results show that,by calculating the density of states,the double occupancy number and the Fermi surface of the system,the metal-Mott insulating phase transition(e.g.,U_(C)/t=6.5 at T/t=0.2)through which the oxygen atom passes as the interaction increases is a secondary phase transition.Due to the temperature-dependent formation of Kondo resonance peaks in the system,the Fermi surface of the hydrogen atom always has a sharp Fermi liquid peak.The double-layer ice experiment is used as a basis to simulate the process of quantum phase transition occurring in it,and the calculation results will provide a theoretical reference for the study of strong correlation of double-layer ice.