The
main activity of this group is addressed to the study of phase
diagrams, quantum phase transitions, electronpair correlation
functions, and effective electronelectron interactions in
systems of electrons having dimensionality D = 3, 2, and
D = 1. Many of the
electronelectron interaction effects in simple metals and
semiconductors can be understood by reference to the homogeneous
electrongas model. A central role is played by the
electronpair distribution functions $g^{\sigma \sigma'} (r)$.
An accurate knowledge of this function is crucial for
applications of density functional theory in various schemes
that have been proposed to transcend the local density
approximation in the construction of exchange and correlation
energy functional. Early our calculations of the pair
distribution functions in the 3D and 2D electron gas were
based on the use of a BijlJastrow correlated wave function.
These early results were confirmed with the advent of the
Quantum Monte Carlo techniques, which have produced a wealth of
accurate data on correlation and response functions over a wide
range of coupling strength for both the 3D and the 2D in
quantum liquids case. In
our last work , we introduce a model for an effective
potential to improve the one which enters the Fermi hypernetted
chain equations. Our study is limited to the 2D system in
which the correlation effects are stronger and most of the
approximations fail to give good results for the pair
correlation function even in the intermediate coupling region.
We have used this accurate knowledge of the pair distribution
functions to study the magnetic phase diagram of the 2D electron
gas. The paramagnetictoferromagnetic quantum phase transition
has been recently predicted to occur at a value of r_{s}≈25
in close agreement
with stateoftheart QMC simulation results. We invite " researchers or PhD students" who are interested in working on these subjects to collaborate.

People: 

R. Asgari (Full time)  F. Parhizgar (Postdoc)  N. Nafari (Part time)  S. Abedinpour (Part time)  A. Esmailpour, (Part time, Shahid Rajaei U.)  A. Ghorbanzadeh (Part time)  M. Zare PhD Student (IPM) 