2013/11/05 by Hai Tao Wang, Wang, Hai Tao, Sam Young Cho +1
Physics and Astronomy · Computer Science · #Quantum many-body systems #Quantum Computing Algorithms and Architecture #Quantum and electron transport phenomena
paper · pdf · doi:10.48550/arxiv.1311.1273
In order to investigate the quantum phase transition in the one-dimensional\nquantum compass model, we numerically calculate non-local string correlations,\nentanglement entropy, and fidelity per lattice site by using the infinite\nmatrix product state representation with the infinite time evolving block\ndecimation method. In the whole range of the interaction parameters, we find\nthat the four distinct string orders characterize the four different Haldane\nphases and the topological quantum phase transition occurs between the Haldane\nphases. The critical exponents of the string order parameters \β=1/8 and\nthe cental charges c=1/2 at the critical points show that the topological phase\ntransitions between the phases belong to an Ising type of universality classes.\nIn addition to the string order parameters, the singularities of the second\nderivative of the ground state energies per site, the continuous and singular\nbehaviors of the von Neumann entropy, and the pinch points of the fidelity per\nlattice site manifest that the phase transitions between the phases are of the\nsecond-order, in contrast to the first-order transition suggested in pervious\nstudies.\n