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Pure Mott phase in the fermion-Hubbard model with spatially varying tunneling. Chen Ahai and Gao Xianlong. Department of Physics, Zhejiang Normal University, Jinhua, 321004, China. >Introduction.
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Pure Mott phase in the fermion-Hubbard model with spatially varying tunneling Chen Ahai and Gao Xianlong Department of Physics, Zhejiang Normal University, Jinhua, 321004, China
>Introduction • It is feasible for us to realize Mott phase in optical lattices with atoms (bosons or fermions) trapped in a harmonic external potential. • the Mott phase is always surrounded by metallic phase. The phase transformation of general formed hubbard model with harmonic external potential in optical lattices.
>The Model • A pure Mott phase can be realized in system with spatially varying tunneling. • Fermion-Hubbard model with spatially varying tunneling: Tunneling of atoms in optical lattices described by fermion-Hubbard model with spatially varying tunneling. Tunneling of trapped atoms in optical lattices described by Hubbard model with harmonic external potential. • The calculations here are performed using the DMRG method.
>Results • Parameters: U=4, L=70, =-2~6.9. • Density distribution. • correlation functions. Density distribution The Fourier transformation of Spin correlation function. The Fourier transformation of Charge correlation function.
>Phases The width of Mott phase and the relevant positions of various phases. Vacuum Mix (vacuum+superfluid) Superfluid Mix (superfluid+Mott phase) Pure Mott phase Mix (superfluid+Mott phase) Superfluid Mix (superfluid+band) band
>Phase diagram and scaling Phase diagram as a function of chemical potential and on-site interactions U. Phase diagram as a function of t/U and . The fluctuation of system with length up to 600.