7 research outputs found
U(1) symmetry breaking in one-dimensional Mott insulator studied by the Density Matrix Renormalization Group method
A new type of external fields violating the particle number preservation is
studied in one-dimensional strongly correlated systems by the Density Matrix
Renormalization Group method. Due to the U(1) symmetry breaking, the ground
state has fluctuation of the total particle number, which implies injection of
electrons and holes from out of the chain. This charge fluctuation can be
relevant even at half-filling because the particle-hole symmetry is preserved
with the finite effective field. In addition, we discuss a quantum phase
transition obtained by considering the symmetry-breaking fields as a mean field
of interchain-hopping.Comment: 7 pages, 4 figure