https://doi.org/10.1140/epjd/e20020039
Systematic field-theory for the hard-core one-component plasma
1
Max-Planck-Institute of Colloids and Interfaces,
14424 Potsdam, Germany
2
Moscow State University, Physics Department,
Moscow 119899, Russia
3
Sektion Physik, Ludwig-Maximilians-Universität, Theresienstr. 37, 80333 München, Germany
Corresponding author: a netz@mpikg-golm.mpg.de
Received:
18
June
2001
Revised:
4
October
2001
Published online: 15 March 2002
An accurate and systematic equation of state for the hard-core
one-component
plasma (HCOCP) is obtained. The result is based on the
Hubbard-Schofield
transformation which yields the field-theoretical Hamiltonian, with
coefficients
expressed in terms of equilibrium correlation functions of the
reference
hard-core fluid.
Explicit calculations were performed using the Gaussian approximation
for the
effective Hamiltonian and
known thermodynamic and structural properties of the reference
hard-core fluid.
For small values of the plasma parameter Γ and packing fraction
the Debye-Hückel result is recovered, while for ,
the excess free energy Fex and internal Uex energy depend
linearly on Γ. The obtained expression for Uex is in a
good agreement with the available Monte Carlo data for the HCOCP. We
also
analyse the validity of the widely used approximation, which
represents the free energy as a sum of the hard-core and
electrostatic part.
PACS: 52.25.Kn – Thermodynamics of plasmas / 61.20.Gy – Theory and models of liquid structure / 05.20.-y – Classical statistical mechanics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002