747 research outputs found
Universal scaling behavior of the single electron box in the strong tunneling limit
We perform a numerical analysis of recently proposed scaling functions for
the single electron box. Specifically, we study the ``magnetic'' susceptibility
as a function of tunneling conductance and gate charge, and the effective
charging energy at zero gate charge as a function of tunneling conductance in
the strong tunneling limit. Our Monte Carlo results confirm the accuracy of the
theoretical predictions.Comment: Published versio
Correlation amplitude for the XXZ spin chain in the disordered regime
We proposed an analytical expression for the amplitude defining the long
distance asymptotic of the correlation function .Comment: 5 pages, harvmac.tex, one epsf figur
Fermionic screening operators in the sine-Gordon model
Extending our previous construction in the sine-Gordon model, we show how to
introduce two kinds of fermionic screening operators, in close analogy with
conformal field theory with c<1.Comment: 18 pages, 1 figur
Nonperturbative study of the two-frequency sine-Gordon model
The two-frequency sine-Gordon model is examined. The focus is mainly on the
case when the ratio of the frequencies is 1/2, given the recent interest in the
literature. We discuss the model both in a perturbative (form factor
perturbation theory) and a nonperturbative (truncated conformal space approach)
framework, and give particular attention to a phase transition conjectured
earlier by Delfino and Mussardo. We give substantial evidence that the
transition is of second order and that it is in the Ising universality class.
Furthermore, we check the UV-IR operator correspondence and conjecture the
phase diagram of the theory.Comment: Minor corrections, LaTeX2e, 39 pages, 26 figures (4 pslatex, 1
postscript and 21 eps
Form-factors of the sausage model obtained with bootstrap fusion from sine-Gordon theory
We continue the investigation of massive integrable models by means of the
bootstrap fusion procedure, started in our previous work on O(3) nonlinear
sigma model. Using the analogy with SU(2) Thirring model and the O(3) nonlinear
sigma model we prove a similar relation between sine-Gordon theory and a
one-parameter deformation of the O(3) sigma model, the sausage model. This
allows us to write down a free field representation for the
Zamolodchikov-Faddeev algebra of the sausage model and to construct an integral
representation for the generating functions of form-factors in this theory. We
also clear up the origin of the singularities in the bootstrap construction and
the reason for the problem with the kinematical poles.Comment: 16 pages, revtex; references added, some typos corrected. Accepted
for publication in Physical Review
Free field representation for the O(3) nonlinear sigma model and bootstrap fusion
The possibility of the application of the free field representation developed
by Lukyanov for massive integrable models is investigated in the context of the
O(3) sigma model. We use the bootstrap fusion procedure to construct a free
field representation for the O(3) Zamolodchikov- Faddeev algebra and to write
down a representation for the solutions of the form-factor equations which is
similar to the ones obtained previously for the sine-Gordon and SU(2) Thirring
models. We discuss also the possibility of developing further this
representation for the O(3) model and comment on the extension to other
integrable field theories.Comment: 14 pages, latex, revtex v3.0 macro package, no figures Accepted for
publication in Phys. Rev.
The Maxwell-Bloch Theory in Quantum Optics and the Kondo Model
In this letter, the problem of radiation in a fiber geometry interacting with
a two level atom is mapped onto the anisotropic Kondo model. Thermodynamical
and dynamical properties are then computed exploiting the integrability of this
latter system. We compute some correlation functions, decay rates and Lamb
shifts. In turn this leads to an analysis of the classical limit of the
anisotropic Kondo model.Comment: 4 pages, 1 figure. In Latex. Uses Revte
On the Finite Temperature Formalism in Integrable Quantum Field Theories
Two different theoretical formulations of the finite temperature effects have
been recently proposed for integrable field theories. In order to decide which
of them is the correct one, we perform for a particular model an explicit check
of their predictions for the one-point function of the trace of the
stress-energy tensor, a quantity which can be independently determined by the
Thermodynamical Bethe Ansatz.Comment: 12 pages, corrected some typos and an equatio
On scaling fields in Ising models
We study the space of scaling fields in the symmetric models with the
factorized scattering and propose simplest algebraic relations between form
factors induced by the action of deformed parafermionic currents. The
construction gives a new free field representation for form factors of
perturbed Virasoro algebra primary fields, which are parafermionic algebra
descendants. We find exact vacuum expectation values of physically important
fields and study correlation functions of order and disorder fields in the form
factor and CFT perturbation approaches.Comment: 2 Figures, jetpl.cl
One-point functions in integrable quantum field theory at finite temperature
We determine the form factor expansion of the one-point functions in
integrable quantum field theory at finite temperature and find that it is
simpler than previously conjectured. We show that no singularities are left in
the final expression provided that the operator is local with respect to the
particles and argue that the divergences arising in the non-local case are
related to the absence of spontaneous symmetry breaking on the cylinder. As a
specific application, we give the first terms of the low temperature expansion
of the one-point functions for the Ising model in a magnetic field.Comment: 10 pages, late
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