https://doi.org/10.1140/epjb/e2005-00031-9
Phase diagram in the quantum XY model with long-range interactions
Instituto de Ciências Exatas,
Departamento de Física,
Universidade Federal do Amazonas, 3000-Japiim,
69077-000, Manaus-AM, Brazil
Corresponding author: a jsousa@ufam.edu.br
Received:
7
February
2004
Revised:
23
August
2004
Published online:
11
February
2005
We study the d-dimensional quantum XY model with ferromagnetic long-range
interaction decaying as 
in terms of boson operators, by employing
the coherent state path integral approach. We have obtained a finite
critical temperature as a function of the dimension (d) for d<p<2d. For
p>2d the system becomes disordered at all temperatures. For the particular
values p=3/2 and d=1 our theoretical calculations are comparable to
those from Monte Carlo simulations.
PACS: 64.60.Ak – Renormalization-group, fractal, and percolation studies of phase transitions / 64.60.Fr – Equilibrium properties near critical points, critical exponents / 68.35.Rh – Phase transitions and critical phenomena
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
