Results 1  10
of
14
Critical phenomena and renormalizationgroup theory
, 2008
"... We review results concerning the critical behavior of spin systems at equilibrium. We consider the Ising and the general O(N)symmetric universality class. For each of them, we review the estimates of the critical exponents, of the equation of state, of several amplitude ratios, and of the twopoint ..."
Abstract

Cited by 56 (12 self)
 Add to MetaCart
(Show Context)
We review results concerning the critical behavior of spin systems at equilibrium. We consider the Ising and the general O(N)symmetric universality class. For each of them, we review the estimates of the critical exponents, of the equation of state, of several amplitude ratios, and of the twopoint function of the order parameter. We report results in three and two dimensions. We discuss the crossover phenomena that are observed in this class of systems. In particular, we review the fieldtheoretical and numerical studies of systems with mediumrange interactions. Moreover, we consider several examples of magnetic and structural phase transitions, which are described by more complex LandauGinzburgWilson Hamiltonians, such as Ncomponent systems with cubic anisotropy, O(N)symmetric systems in the presence of quenched disorder, frustrated spin systems with noncollinear or canted order, and finally, a class of systems described by the tetragonal LandauGinzburgWilson Hamiltonian with three quartic couplings. The results for the tetragonal Hamiltonian are original, in particular we present the sixloop perturbative series for the βfunctions and the critical exponents.
Monopoles in 2 + 1dimensional conformal field theories with global U(1) symmetry
"... In 2 + 1dimensional conformal field theories with a global U(1) symmetry, monopoles can be introduced through a background gauge field that couples to the U(1) conserved current. We use the stateoperator correspondence to calculate scaling dimensions of such monopoles. We obtain the nexttoleadin ..."
Abstract

Cited by 3 (2 self)
 Add to MetaCart
(Show Context)
In 2 + 1dimensional conformal field theories with a global U(1) symmetry, monopoles can be introduced through a background gauge field that couples to the U(1) conserved current. We use the stateoperator correspondence to calculate scaling dimensions of such monopoles. We obtain the nexttoleading term in the 1/Nb expansion of the WilsonFisher fixed point in the theory of Nb complex bosons.
Yejin Huh Quantum Phase Transitions in dwave Superconductors
, 2011
"... Strongly correlated systems are of interest due to their exotic collective behavior. In this thesis we study low energy effective theory and quantum phase transitions of dwave superconductors and spin liquids. First we examine the quantum theory of the spontaneous breaking of lattice rotation symme ..."
Abstract
 Add to MetaCart
(Show Context)
Strongly correlated systems are of interest due to their exotic collective behavior. In this thesis we study low energy effective theory and quantum phase transitions of dwave superconductors and spin liquids. First we examine the quantum theory of the spontaneous breaking of lattice rotation symmetry in dwave superconductors on the square lattice. This is described by a field theory of an Ising nematic order parameter coupled to the gapless fermionic quasiparticles. We determine the structure of the renormalization group to all orders in a 1/Nf expansion, where Nf is the number of fermion spin components. Asymptotically exact results are obtained for the quantum critical theory in which, as in the large Nf theory, the nematic order has a large anomalous dimension, and the fermion spectral functions are highly anisotropic. Next we study quantum phase transitions in antiferromagnetic kagome lattices. Due to the high geometric frustration, this system poses as a good candidate for a spin liquid with exotic excitations. Here we look at physics of the spinon and vison
λtransition: A Monte Carlo study of an
, 904
"... The specific heat of thin films near the ..."
(Show Context)
Exact FiniteSizeScaling Corrections to the Critical TwoDimensional Ising Model on a Torus
, 2008
"... We analyze the finitesize corrections to the energy and specific heat of the critical twodimensional spin1/2 Ising model on a torus. We extend the analysis of Ferdinand and Fisher to compute the correction of order L −3 to the energy and the corrections of order L −2 and L −3 to the specific heat ..."
Abstract
 Add to MetaCart
We analyze the finitesize corrections to the energy and specific heat of the critical twodimensional spin1/2 Ising model on a torus. We extend the analysis of Ferdinand and Fisher to compute the correction of order L −3 to the energy and the corrections of order L −2 and L −3 to the specific heat. We also obtain general results on the form of the finitesize corrections to these quantities: only integer powers of L −1 occur, unmodified by logarithms; and the energy expansion contains only odd powers of L −1. In the specificheat expansion any power of L −1 can appear, but the coefficients of the odd powers are proportional to the corresponding coefficients of the energy expansion. Key Words: Ising model; finitesize scaling; corrections to scaling. It is wellknown that phase transitions in statisticalmechanical systems can occur only in the infinitevolume limit. In any finite system, all thermodynamic quantities (such as the magnetic susceptibility and the specific heat) are analytic functions of
thermodynamic Casimir force in the
, 907
"... The specific heat, the energy density and the ..."
(Show Context)
unknown title
"... Finitetemperature chiral transition in QCD with quarks in the fundamental and adjoint representation. ..."
Abstract
 Add to MetaCart
(Show Context)
Finitetemperature chiral transition in QCD with quarks in the fundamental and adjoint representation.
A Monte Carlo study of threedimensional
, 811
"... KosterlitzThouless transition in thin films: ..."
(Show Context)
Yet an other method to compute the thermodynamic Casimir force in lattice models
, 908
"... We discuss a method that allows to compute the thermodynamic Casimir force at a given temperature in lattice models by performing a single Monte Carlo simulation. It is analogous to the one used by de Forcrand and Noth and de Forcrand, Lucini and Vettorazzo in the study of ’t Hooft loops and the int ..."
Abstract
 Add to MetaCart
(Show Context)
We discuss a method that allows to compute the thermodynamic Casimir force at a given temperature in lattice models by performing a single Monte Carlo simulation. It is analogous to the one used by de Forcrand and Noth and de Forcrand, Lucini and Vettorazzo in the study of ’t Hooft loops and the interface tension in SU(N) lattice gauge models in four dimensions. We test the method at the example of thin films in the XY universality class. In particular we simulate the improved twocomponent φ 4 model on the simple cubic lattice. This allows us to compare with our previous study, where we have computed the Casimir force by numerically integrating energy densities over the inverse temperature.
unknown title
, 810
"... We simulate lattice models in the threedimensional XY universality class in the low and the high temperature phase. This allows us to compute a number of universal amplitude ratios with unprecedented precision: RΥ = 0.411(2), RB = 2.83(1), R + = 0.3562(10) and R − = 0.850(5). These results ξ ξ can ..."
Abstract
 Add to MetaCart
(Show Context)
We simulate lattice models in the threedimensional XY universality class in the low and the high temperature phase. This allows us to compute a number of universal amplitude ratios with unprecedented precision: RΥ = 0.411(2), RB = 2.83(1), R + = 0.3562(10) and R − = 0.850(5). These results ξ ξ can be compared with those obtained from other theoretical methods, such as field theoretic methods or the high temperature series expansion and also with experimental results for the λtransition of 4He. In addition to the XY model, we study the threedimensional twocomponent φ4 model on the simple cubic lattice. The parameter of the φ4 model is chosen such that leading corrections to scaling are small.