2,299 research outputs found
Evidence for the super Tonks-Girardeau gas
We provide evidence in support of a recent proposal by Astrakharchik at al.
for the existence of a super Tonks-Girardeau gas-like state in the attractive
interaction regime of quasi-one-dimensional Bose gases. We show that the super
Tonks-Giradeau gas-like state corresponds to a highly-excited Bethe state in
the integrable interacting Bose gas for which the bosons acquire hard-core
behaviour. The gas-like state properties vary smoothly throughout a wide range
from strong repulsion to strong attraction. There is an additional stable
gas-like phase in this regime in which the bosons form two-body bound states
behaving like hard-core bosons.Comment: 10 pages, 1 figure, 2 tables, additional text on the stability of the
super T-G gas-like stat
Free energies and critical exponents of the A_1^{(1)}, B_n^{(1)}, C_n^{(1)} and D_n^{(1)} face models
We obtain the free energies and critical exponents of models associated with
elliptic solutions of the star-triangle relation and reflection equation. The
models considered are related to the affine Lie algebras A_1^{(1)},
B_n^{(1)},C_n^{(1)} and D_n^{(1)}. The bulk and surface specific heat exponents
are seen to satisfy the scaling relation 2\alpha_s = \alpha_b + 2. It follows
from scaling relations that in regime III the correlation length exponent \nu
is given by \nu=(l+g)/2g, where l is the level and g is the dual Coxeter
number. In regime II we find \nu=(l+g)/2l.Comment: 9 pages, Latex, no figure
Variational approach to the scaling function of the 2D Ising model in a magnetic field
The universal scaling function of the square lattice Ising model in a
magnetic field is obtained numerically via Baxter's variational corner transfer
matrix approach. The high precision numerical data is in perfect agreement with
the remarkable field theory results obtained by Fonseca and Zamolodchikov, as
well as with many previously known exact and numerical results for the 2D Ising
model. This includes excellent agreement with analytic results for the magnetic
susceptibility obtained by Orrick, Nickel, Guttmann and Perk. In general the
high precision of the numerical results underlines the potential and full power
of the variational corner transfer matrix approach.Comment: 12 pages, 1 figure, 4 tables, v2: minor corrections, references adde
Scaling and universality in the 2D Ising model with a magnetic field
The scaling function of the 2D Ising model in a magnetic field on the square
and triangular lattices is obtained numerically via Baxter's variational corner
transfer matrix approach. The use of the Aharony-Fisher non-linear scaling
variables allowed us to perform calculations sufficiently away from the
critical point to obtain very high precision data, which convincingly confirm
all predictions of the scaling and universality hypotheses. The results are in
excellent agreement with the field theory calculations of Fonseca and
Zamolodchikov as well as with many previously known exact and numerical results
for the 2D Ising model. This includes excellent agreement with the classic
analytic results for the magnetic susceptibility by Barouch, McCoy, Tracy and
Wu, recently enhanced by Orrick, Nickel, Guttmann and Perk.Comment: 5 pages, 1 figur
Motion and homogenization of vortices in anisotropic Type II superconductors
The motion of vortices in an anisotropic superconductor is considered. For a system of well-separated vortices, each vortex is found to obey a law of motion analogous to the local induction approximation, in which velocity of the vortex depends upon the local curvature and orientation. A system of closely packed vortices is then considered, and a mean field model is formulated in which the individual vortex lines are replaced by a vortex density
Killing spinors are Killing vector fields in Riemannian Supergeometry
A supermanifold M is canonically associated to any pseudo Riemannian spin
manifold (M_0,g_0). Extending the metric g_0 to a field g of bilinear forms
g(p) on T_p M, p\in M_0, the pseudo Riemannian supergeometry of (M,g) is
formulated as G-structure on M, where G is a supergroup with even part G_0\cong
Spin(k,l); (k,l) the signature of (M_0,g_0). Killing vector fields on (M,g)
are, by definition, infinitesimal automorphisms of this G-structure. For every
spinor field s there exists a corresponding odd vector field X_s on M. Our main
result is that X_s is a Killing vector field on (M,g) if and only if s is a
twistor spinor. In particular, any Killing spinor s defines a Killing vector
field X_s.Comment: 14 pages, latex, one typo correcte
A refined Razumov-Stroganov conjecture II
We extend a previous conjecture [cond-mat/0407477] relating the
Perron-Frobenius eigenvector of the monodromy matrix of the O(1) loop model to
refined numbers of alternating sign matrices. By considering the O(1) loop
model on a semi-infinite cylinder with dislocations, we obtain the generating
function for alternating sign matrices with prescribed positions of 1's on
their top and bottom rows. This seems to indicate a deep correspondence between
observables in both models.Comment: 21 pages, 10 figures (3 in text), uses lanlmac, hyperbasics and epsf
macro
Minimal Unitary Models and The Closed SU(2)-q Invariant Spin Chain
We consider the Hamiltonian of the closed invariant chain. We
project a particular class of statistical models belonging to the unitary
minimal series. A particular model corresponds to a particular value of the
coupling constant. The operator content is derived. This class of models has
charge-dependent boundary conditions. In simple cases (Ising, 3-state Potts)
corresponding Hamiltonians are constructed. These are non-local as the original
spin chain.Comment: 19 pages, latex, no figure
One-Dimensional Impenetrable Anyons in Thermal Equilibrium. IV. Large Time and Distance Asymptotic Behavior of the Correlation Functions
This work presents the derivation of the large time and distance asymptotic
behavior of the field-field correlation functions of impenetrable
one-dimensional anyons at finite temperature. In the appropriate limits of the
statistics parameter, we recover the well-known results for impenetrable bosons
and free fermions. In the low-temperature (usually expected to be the
"conformal") limit, and for all values of the statistics parameter away from
the bosonic point, the leading term in the correlator does not agree with the
prediction of the conformal field theory, and is determined by the singularity
of the density of the single-particle states at the bottom of the
single-particle energy spectrum.Comment: 26 pages, RevTeX
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