Path Integral Monte Carlo Simulations Of The Warm Dense Electron Systems

Warm dense electron system has been the focus of research,Path Integral Monte Carlo(PIMC)method is an important method to study the problem.In this paper,we utilize the recently proposed configuration path integral Monte Carlo(CPIMC)method to simulate the interacting fermions in a one-dimensional harmonic trap and the degenerate electron gas,thermodynamic equilibrium properties under different conditions are obtained.When the electrons are in the condition of high degeneracy,the quantum exchange effect is very significant,and the traditional PIMC method will encounter the so-called Fermion Sign Problem(FSP),which leads to a low computation efficiency.On the other hand,the CPIMC method takes into account the anti-symmetry of fermion,solves the FSP,and is suitable for the computation of the high degenerate system.By means of the method,we simulate the multi-electron system under high degenerate condition.The total energy of the system is obtained,and the corresponding FSP is very slight.But as the interaction between the electrons increases,the FSP becomes more and more serious.In this paper,a further study on the FSP is presented,and three possible solutions to improve this method are proposed.To a certain extent,the improved scheme alleviates the FSP,and it also reflects that the FSP of the method is mainly due to the non-adaptability of the single particle state.