Finite-temperature behavior of anisotropic two-sublattice magnets

Finite-temperature behavior of anisotropic two-sublattice magnets

Finite temperature behavior of strongly disordered quantum magnets coupled to a dissipative bath

We study the effect of dissipation on the infinite randomness fixed point and the Griffiths–McCoy singularities of random transverse Ising systems in chains, ladders and in two dimensions. A strong disorder renormalization group scheme is presented that allows the computation of the finite temperature behavior of the magnetic susceptibility and the spin specific heat. In the case of ohmic dissi...

Phase transitions in two-dimensional anisotropic quantum magnets

We consider quantumHeisenberg ferroand antiferromagnets on the square lattice with exchange anisotropy of easy-plane or easy-axis type. The thermodynamics and the critical behaviour of the models are studied by the pure-quantum self-consistent harmonic approximation, in order to evaluate the spin and anisotropy dependence of the critical temperatures. Results for thermodynamic quantities are re...

Time-dependent correlations in quantum magnets at finite temperature

B. Fauseweh,1,* F. Groitl,2,3,† T. Keller,4,5 K. Rolfs,6 D. A. Tennant,7 K. Habicht,8 and G. S. Uhrig1,‡ 1Lehrstuhl für Theoretische Physik I, Technische Universität Dortmund, Otto-Hahn Straße 4, 44221 Dortmund, Germany 2Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland 3Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, ...

Renormalization-group approach to anisotropic superconductors at finite temperature.

A renormalization group (RG) analysis of the superconductive instability of an anisotropic fermionic system is developed at a finite temperature. The method appears a natural generalization of Shankar’s approach to interacting fermions and of Weinberg’s discussion about anisotropic superconductors at T = 0. The need of such an extension is fully justified by the effectiveness of the RG at the c...