Partenaires

CNRS
UPS



Rechercher

Sur ce site

Sur le Web du CNRS


Accueil du site > Séminaires > Séminaires 2015 > A functional renormalization group approach to quantum spin models

Mardi 27 janvier 2015-14:00

A functional renormalization group approach to quantum spin models

Adam Rançon (Laboratoire de Physique, Ecole Normale Superieure de Lyon)

par Gabriel LeMarié - 27 janvier 2015

In this talk, I will present a recent application of the lattice functional renormalization group (FRG) to quantum XY spin models using a mapping to hardcore bosons. This mapping allows for the reinterpretation of the spontaneous magnetization in spin systems as the Bose condensation of magnons, and gives a natural framework to implement the lattice FRG. I will show how the FRG can take the hardcore constraint into account exactly, and will discuss the simplest approximation schemes. The results are in good agreement with Monte-Carlo simulations in two and three dimensions, and shows how the phase diagram can be reinterpreted at low densities using Bogoliubov theory.

Post-scriptum :

contact : N. Laflorencie