258 research outputs found
Lattice simulation of ultracold atomic Bose-Fermi mixtures
Bose-Fermi mixtures have been recently realized and invesitigated in
ultracold atomic experiments. We formulate quantum Monte Carlo simulation of
Bose-Fermi mixtures on the (3+1)-dimensional lattice. As its first application,
we analyze the boson-fermion pair correlation and the phase diagram of the
Bose-Einstein condensation.Comment: Talk given at 30th International Symposium On Lattice Field Theory
(Lattice 2012), Cairns Convention Centre, Cairns, Australi
One-dimensional anyons in relativistic field theory
We study relativistic anyon field theory in 1+1 dimensions. While
(2+1)-dimensional anyon fields are equivalent to boson or fermion fields
coupled with the Chern-Simons gauge fields, (1+1)-dimensional anyon fields are
equivalent to boson or fermion fields with many-body interaction. We derive the
path integral representation and perform the lattice Monte Carlo simulation
Non-Abelian vortex in lattice gauge theory
We perform the Monte Carlo study of the SU(3) non-Abelian Higgs model. We
discuss phase structure and non-Abelian vortices by gauge invariant operators.
External magnetic fields induce non-Abelian vortices in the color-flavor locked
phase. The spatial distribution of non-Abelian vortices suggests the repulsive
vortex-vortex interaction
Lattice QCD with mismatched Fermi surfaces
We study two flavor fermions with mismatched chemical potentials in quenched
lattice QCD. We first consider a large isospin chemical potential, where a
charged pion is condensed, and then introduce a small mismatch between the
chemical potentials of the up quark and the anti-down quark. We find that the
homogeneous pion condensate is destroyed by the mismatch of the chemical
potentials. We also find that the two-point correlation function shows spatial
oscillation, which indicates an inhomogeneous ground state, although it is not
massless but massive in the present simulation setup
Lattice QCD in curved spacetimes
We formulate the lattice QCD simulation with background classical
gravitational fields. This formulation enables us to study nonperturbative
aspects of quantum phenomena in curved spacetimes from the first principles. As
the first application, we perform the simulation with the
Friedmann-Lemaitre-Robertson-Walker metric and analyze particle production in
the expanding universe
Berry phase in lattice QCD
We propose the lattice QCD calculation of the Berry phase which is defined by
the ground state of a single fermion. We perform the ground-state projection of
a single-fermion propagator, construct the Berry link variable on a
momentum-space lattice, and calculate the Berry phase. As the first
application, the first Chern number of the (2+1)-dimensional Wilson fermion is
calculated by the Monte Carlo simulation
Lattice QCD with strong external electric fields
We study particle generation by a strong electric field in lattice QCD. To
avoid the sign problem of the Minkowskian electric field, we adopt the
"isospin" electric charge. When a strong electric field is applied, the
insulating vacuum is broken down and pairs of charged particles are produced by
the Schwinger mechanism. The competition against the color confining force is
also discussed
Lattice study of the chiral magnetic effect in a chirally imbalanced matter
We investigate the chiral magnetic effect by lattice QCD with a chiral
chemical potential. In a chirally imbalanced matter, we obtain a finite induced
current along an external magnetic field. We analyze the dependence on the
lattice spacing, the temperature, the spatial volume, and the fermion mass. The
present result indicates that the continuum limit is important for the
quantitative argument of the strength of the induced current
Complex Langevin simulation in condensed matter physics
The complex Langevin method is one hopeful candidate to tackle the sign
problem. This method is applicable not only to QCD but also to nonrelativistic
field theory, such as condensed matter physics. We present the simulation
results of a rotating Bose gas and an imbalanced Fermi-Hubbard model.Comment: Talk given at the 33rd International Symposium on Lattice Field
Theory (LATTICE 2015
Magnetism and rotation in relativistic field theory
We investigate the analogy between magnetism and rotation in relativistic
theory. In nonrelativistic theory, the exact correspondence between magnetism
and rotation is established in the presence of an external trapping potential.
Based on this, we analyze relativistic rotation under external trapping
potentials. A Landau-like quantization is obtained by considering an
energy-dependent potential.Comment: 8 pages, 1 figur
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