Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, Connecticut 06520, USA.
Phys Rev Lett. 2012 Jul 20;109(3):032503. doi: 10.1103/PhysRevLett.109.032503. Epub 2012 Jul 17.
The shell model Monte Carlo method is a powerful technique to calculate thermal and ground-state properties of strongly correlated finite-size systems. However, its application to odd-particle-number systems has been hampered by the sign problem that originates from the projection on an odd number of particles. We circumvent this sign problem for the ground-state energy by extracting the ground-state energy of the odd-particle-number system from the asymptotic behavior of the imaginary-time single-particle Green's function of the even-particle-number system. We apply this method to calculate pairing gaps of nuclei in the iron region. Our results are in good agreement with experimental pairing gaps.
壳模型蒙特卡罗方法是一种强大的技术,可用于计算强关联有限系统的热和基态性质。然而,由于奇数粒子投影产生的符号问题,其在奇数粒子数系统中的应用受到了阻碍。我们通过从偶数粒子数系统的虚时间单粒子格林函数的渐近行为中提取奇数粒子数系统的基态能量,来解决基态能量的符号问题。我们将此方法应用于计算铁区原子核的配对能隙。我们的结果与实验配对能隙吻合良好。