5 research outputs found
Inhomogeneous Condensates in the Thermodynamics of the Chiral NJL_2 model
We analyze the thermodynamical properties, at finite density and nonzero
temperature, of the (1+1)-dimensional chiral Gross-Neveu model (the NJL_2
model), using the exact inhomogeneous (crystalline) condensate solutions to the
gap equation. The continuous chiral symmetry of the model plays a crucial role,
and the thermodynamics leads to a broken phase with a periodic spiral
condensate, the "chiral spiral", as a thermodynamically preferred limit of the
more general "twisted kink crystal" solution of the gap equation. This
situation should be contrasted with the Gross-Neveu model, which has a discrete
chiral symmetry, and for which the phase diagram has a crystalline phase with a
periodic kink crystal. We use a combination of analytic, numerical and
Ginzburg-Landau techniques to study various parts of the phase diagram.Comment: 28 pages, 13 figure