中国物理B ›› 2022, Vol. 31 ›› Issue (11): 110205-110205.doi: 10.1088/1674-1056/ac8a8f
Yueshui Zhang(张越水)1,2 and Lei Wang(王磊)3,4,†
Yueshui Zhang(张越水)1,2 and Lei Wang(王磊)3,4,†
摘要: We study the structure of the continuous matrix product operator (cMPO)[1] for the transverse field Ising model (TFIM). We prove TFIM's cMPO is solvable and has the form $T=\rm{e}^{-\frac{1}{2}\hat{H}_{\rm F}}$. $\hat{H}_{\rm F}$ is a non-local free fermionic Hamiltonian on a ring with circumference $\beta$, whose ground state is gapped and non-degenerate even at the critical point. The full spectrum of $\hat{H}_{\rm F}$ is determined analytically. At the critical point, our results verify the state-operator-correspondence[2] in the conformal field theory (CFT). We also design a numerical algorithm based on Bloch state ansatz to calculate the low-lying excited states of general (Hermitian) cMPO. Our numerical calculations coincide with the analytic results of TFIM. In the end, we give a short discussion about the entanglement entropy of cMPO's ground state.
中图分类号: (Computational techniques; simulations)