Fieldinduced BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems: A renormalizationgroup study
Abstract
We use the renormalizationgroup method to study the magnetic field influence on the BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems. We first considered a model with SU(2) symmetry (universality class z=1) and we obtain for the critical magnetic field a power law dependence on the critical temperature, [H{sub c}(T)H{sub c}(0)]{approx}T{sup 2}. In the case of U(1) symmetry (universality class z=2) the dependence is different, and the magnetic critical field depends linearly on the critical temperature, [H{sub c}(T)H{sub c}(0)]{approx}T. By considering a more relevant model, which includes also the system's anisotropy, we obtain for the same symmetry class a T{sup 3/2} dependence of the magnetic critical field on the critical temperature. We discuss these theoretical predictions of the renormalization group in connection with experimental results reported in the literature.
 Authors:
 Department of Physics, 'BabesBolyai' University, 40084 Cluj Napoca (Romania)
 (United States)
 (Germany)
 Publication Date:
 OSTI Identifier:
 20719819
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 72; Journal Issue: 18; Other Information: DOI: 10.1103/PhysRevB.72.184414; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ANISOTROPY; BOSEEINSTEIN CONDENSATION; CRITICAL FIELD; CRITICAL TEMPERATURE; MAGNONS; RENORMALIZATION; SPIN; SU2 GROUPS; SYMMETRY; THREEDIMENSIONAL CALCULATIONS; U1 GROUPS
Citation Formats
Crisan, M., Grosu, I., Tifrea, I., Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, Bodea, D., and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden. Fieldinduced BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems: A renormalizationgroup study. United States: N. p., 2005.
Web. doi:10.1103/PhysRevB.72.184414.
Crisan, M., Grosu, I., Tifrea, I., Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, Bodea, D., & Max Planck Institute for the Physics of Complex Systems, 01187 Dresden. Fieldinduced BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems: A renormalizationgroup study. United States. doi:10.1103/PhysRevB.72.184414.
Crisan, M., Grosu, I., Tifrea, I., Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, Bodea, D., and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden. Tue .
"Fieldinduced BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems: A renormalizationgroup study". United States.
doi:10.1103/PhysRevB.72.184414.
@article{osti_20719819,
title = {Fieldinduced BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems: A renormalizationgroup study},
author = {Crisan, M. and Grosu, I. and Tifrea, I. and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 and Bodea, D. and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden},
abstractNote = {We use the renormalizationgroup method to study the magnetic field influence on the BoseEinstein condensation of interacting dilute magnons in threedimensional spin systems. We first considered a model with SU(2) symmetry (universality class z=1) and we obtain for the critical magnetic field a power law dependence on the critical temperature, [H{sub c}(T)H{sub c}(0)]{approx}T{sup 2}. In the case of U(1) symmetry (universality class z=2) the dependence is different, and the magnetic critical field depends linearly on the critical temperature, [H{sub c}(T)H{sub c}(0)]{approx}T. By considering a more relevant model, which includes also the system's anisotropy, we obtain for the same symmetry class a T{sup 3/2} dependence of the magnetic critical field on the critical temperature. We discuss these theoretical predictions of the renormalization group in connection with experimental results reported in the literature.},
doi = {10.1103/PhysRevB.72.184414},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 18,
volume = 72,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}

Based on the realistic spin Hamiltonian for the frustrated quasitwodimensional spin1/2 antiferromagnet Cs{sub 2}CuCl{sub 4}, a threedimensional spin ordering in the applied magnetic field B near the saturation value B{sub c} is studied within the magnon BoseEinstein condensation scenario. Using a hardcore boson formulation of the spin model, a strongly anisotropic magnon dispersion in Cs{sub 2}CuCl{sub 4} is calculated. In the dilute magnon limit near B{sub c}, the hardcore boson constraint results in an effective magnon interaction which is treated in the HartreeFock approximation. The critical temperature T{sub c} is calculated as a function of the magnetic field B andmore »

Probing Anomalous Longitudinal Fluctuations of the Interacting Bose Gas via BoseEinstein Condensation of Magnons
The emergence of a finite staggered magnetization in quantum Heisenberg antiferromagnets subject to a uniform magnetic field can be viewed as BoseEinstein condensation of magnons. Using nonperturbative results for the infrared behavior of the interacting Bose gas, we present exact results for the staggered spinspin correlation functions of quantum antiferromagnets in a magnetic field at zero temperature. In particular, we show that in dimensions 1<D{<=}3 the longitudinal dynamic structure factor S{sub parallel}(q,{omega}) describing staggered spin fluctuations in the direction of the staggered magnetization exhibits a critical continuum whose weight can be controlled experimentally by varying the magnetic field. 
BoseEinstein condensation of trapped polaritons in twodimensional electronhole systems in a high magnetic field
The BoseEinstein condensation (BEC) of magnetoexcitonic polaritons (magnetopolaritons) in twodimensional (2D) electronhole system embedded in a semiconductor microcavity in a high magnetic field B is predicted. There are two physical realizations of 2D electronhole system under consideration: a graphene layer and quantum well (QW). A 2D gas of magnetopolaritons is considered in a planar harmonic potential trap. Two possible physical realizations of this trapping potential are assumed: inhomogeneous local stress or harmonic electric field potential applied to excitons and a parabolic shape of the semiconductor cavity causing the trapping of microcavity photons. The effective Hamiltonian of the ideal gas ofmore » 
BoseEinstein condensation temperature of a homogeneous weakly interacting Bose gas: Path integral Monte Carlo study
Using a finitetemperature path integral Monte Carlo simulation (PIMC) method and finitesize scaling, we have investigated the interactioninduced shift of the phasetransition temperature for BoseEinstein condensation of homogeneous weakly interacting Bose gases in three dimensions, which is given by a proposed analytical expression T{sub c}=T{sub c}{sup 0}{l_brace}1+c{sub 1}an{sup 1/3}+[c{sub 2}{sup '} ln(an{sup 1/3})+c{sub 2}]a{sup 2}n{sup 2/3}+O(a{sup 3}n){r_brace}, where T{sub c}{sup 0} is the critical temperature for an ideal gas, a is the swave scattering length, and n is the number density. We have used smaller number densities and more time slices than in the previous PIMC simulations [Gruter et al.,more »