Localization of Mosaic Model with Neighbor Interaction
In this paper,we study the localization problem of mosaic model in a one-dimensional spinless fermi system in an incom-mensurate optical lattice with near neighbor interactions,which realizes the transition from thermalization to multi-body localization by adjusting the intensity of interaction and quasi-periodic potential.The normalized participation rate of the eigenstates correspond-ing to the ground state and the middle sixth energy level in the system is calculated by the exact diagonalization method.It is found that there are mixed phases between the thermal phase and the multi-body local phase.In this region,the excited state corresponding to the intermediate energy level of the system is localized earlier than that corresponding to the ground state,which is different from the mixed phase property of the interaction Aubry-Andre model.By means of density matrix renormalization group and exact diago-nalization method,the density fluctuation function of ground-state single particle excitation,the ratio of neighbor level spacing and entanglement entropy of excited state are calculated,and two phase boundaries of mixed phase are obtained.It can be seen from the phase diagram that the weak quasi-periodic potential can only localize the excited state but not the ground state in the multi-body system,and the existence of the interaction reduces the required quasi-periodic potential strength for the ground state localization.
multi-body localizationthermalizationexact diagonalizationdensity matrix renormalization group
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