标题： 利用虚时关联矩阵提取壳模型蒙特卡罗方法中的光谱 显示英文标题

标题： Extracting spectra in the shell model Monte Carlo method using imaginary-time correlation matrices

摘要： 在组态相互作用(CI)壳模型框架下，用于计算核能级的传统对角化方法在非常大的模型空间中受到限制。 壳模型蒙特卡罗(SMMC)是一种强大的技术，可用于计算非常大的模型空间中核的热学和基态可观测量，但在该方法中提取核谱具有挑战性。 我们提出了一种新颖的方法，用于提取一组良好量子数（如自旋和宇称）特定值下的低激发能级。 该方法基于满足渐近广义特征值问题的虚时间单粒子密度关联矩阵。 我们在一个允许与CI壳模型哈密顿量精确对角化结果进行比较的轻核中验证了该方法。 该方法适用于其他可以用CI壳模型方法描述的有限尺寸量子多体系统。 显示英文摘要

摘要： Conventional diagonalization methods to calculate nuclear energy levels in the framework of the configuration-interaction (CI) shell model approach are prohibited in very large model spaces. The shell model Monte Carlo (SMMC) is a powerful technique for calculating thermal and ground-state observables of nuclei in very large model spaces, but it is challenging to extract nuclear spectra in this approach. We present a novel method to extract low-lying energy levels for given values of a set of good quantum numbers such as spin and parity. The method is based on imaginary-time one-body density correlation matrices that satisfy asymptotically a generalized eigenvalue problem. We validate the method in a light nucleus that allows comparison with exact diagonalization results of the CI shell model Hamiltonian. The method is applicable to other finite-size quantum many-body systems that can be described within a CI shell model approach.