Fermi Liquid Interactions and Properties of 2D Fermi Systems: A Crossing-Symmetric Approach

We develop a crossing-symmetric model for microscopically obtaining Fermi liquid interactions in 2D Fermi systems. Partial re-summation of Feynman diagrams, renormalization of quasiparticle interactions, and the preservation of crossing symmetry leads to coupled, nonlinear integral equations in terms of momentum-dependent Fermi liquid interactions and scattering amplitudes [Ref. 1,2]. Expansion of 2D quasiparticle interactions in terms of Chebyshev polynomials leads to a set of coupled equations that are solved self-consistently using an iterative method. The underlying repulsive or attractive interactions serve as the driving terms. We calculate several physical properties and, in particular, find the 2D system to be robust against ferromagnetic and density instabilities even for sizeable interaction strengths. We also explore pairing properties of the system.

1. K. Quader, K. Bedell, G.E. Brown, Phys. Rev. B36, 156 (1987)

2. T. L. Ainsworth, K. S. Bedell, Phys. Rev. B35, 8425 (1987)