Thermal Excitations of Frustrated Xy Spins in Two Dimensions
نویسندگان
چکیده
We present a new variational approach to the study of phase transitions in frustrated 2D XY models. In the spirit of Villain’s approach for the ferromagnetic case we divide thermal excitations into a low temperature long wavelength part (LW) and a high temperature short wavelength part (SW). In the present work we mainly deal with LW excitations and we explicitly consider the cases of the fully frustrated ∗Laboratoire associé au CNRS
منابع مشابه
Relevance of the fixed dimension perturbative approach to frustrated magnets in two and three dimensions
We show that the critical behavior of twoand three-dimensional frustrated magnets cannot reliably be described from the known fiveand six-loop perturbative renormalization-group results. Our conclusions are based on a careful reanalysis of the resummed perturbative series obtained within the zero-momentum massive scheme. In three dimensions, the critical exponents for XY and Heisenberg spins di...
متن کاملSmectic-like Phase for Modulated Xy Spins in Two Dimensions
The row model for frustrated XY spins on a triangular lattice in 2D is used to study incommensurate (IC) and commensurate (C) phases, in the regime where a (C)-(IC) transition may be observed. Thermodynamic quantities for the (IC) state are computed analytically by means of the NSCHA, a new variational method appropriate for frustrated systems. On the commensurate side of the (C)-(IC) boundary,...
متن کاملar X iv : c on d - m at / 9 41 00 16 v 1 6 O ct 1 99 4 PHASE TRANSITIONS OF FRUSTRATED XY SPINS IN TWO DIMENSIONS
The row model is used to study the commensurate-incommensurate (C-IC) and isotropic (FFTXY) transitions of the frustrated 2D XY model on the triangular lattice. New relevant variables clarify the physics of these transitions: phase and chiral variables are coupled so that spin waves generate long range polar interactions. The resulting dielectric constant diverges at the transition. A single tr...
متن کاملUniversal Short - time Behaviour of the Dynamic Fully Frustrated XY Model ∗
With Monte Carlo methods we investigate the dynamic relaxation of the fully frustrated XY model in two dimensions below or at the Kosterlitz-Thouless phase transition temperature. Special attention is drawn to the sublattice structure of the dynamic evolution. Short-time scaling behaviour is found and universality is confirmed. The critical exponent θ is measured for different temperature and w...
متن کاملDecoupling in the 1D frustrated quantum XY model and Josephson junction ladders: Ising critical behavior
A generalization of the one-dimensional frustrated quantum XY model is considered in which the inter and intra-chain coupling constants of the two infinite XY (planar rotor) chains have different strengths. The model can describe the superconductor to insulator transition due to charging effects in a ladder of Josephson junctions in a magnetic field with half a flux quantum per plaquette. From ...
متن کامل