2,858 research outputs found
Density matrix renormalization group algorithms with a single center site
We develop a correction to the density matrix used in density matrix
renormalization group calculations to take into account the incompleteness of
the environment block. The correction allows successful calculations using only
a single site in the center of the system, rather than the standard two sites,
improving typical computation times by a factor of two to four. In addition, in
many cases where ordinary DMRG can get stuck in metastable configurations, the
correction eliminates the sticking. We test the new method on the Heisenberg
S=1 chain.Comment: 4 pages, 4 figure
Checkerboard patterns in the t-J model
Using the density matrix renormalization group, we study the possibility of
real space checkerboard patterns arising as the ground states of the t-J model.
We find that checkerboards with a commensurate (pi,pi) background are not low
energy states and can only be stabilized with large external potentials.
However, we find that striped states with charge density waves along the
stripes can form approximate checkerboard patterns. These states can be
stabilized with a very weak external field aligning and pinning the CDWs on
different stripes.Comment: 4 pages, 5 figure
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