Pure Mott phase in the fermion-Hubbard model with spatially varying tunneling

1
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
2
gtIntroduction

• 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.
3
gtThe Model

• A pure Mott phase can be realized in system with
  spatially varying tunneling.
• Fermion-Hubbard model with spatially varying
  tunneling

Tunneling of trapped atoms in optical lattices
described by Hubbard model with harmonic external
potential.
Tunneling of atoms in optical lattices described
by fermion-Hubbard model with spatially varying
tunneling.

• The calculations here are performed using the
  DMRG method.

4
gtResults

• Parameters U4, L70, -26.9.
• Density distribution.
• correlation functions.

Density distribution
The Fourier transformation of Spin correlation
function.
The Fourier transformation of Charge correlation
function.
5
gtPhases
The width of Mott phase and the relevant
positions of various phases.
6
gtPhase 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.