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Non-perturbative saddle point for the effective action of disordered and interacting electrons in 2D

Claudio Chamon·Eduardo R. Mucciolo
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Abstract

We find a non-perturbative saddle-point solution for the non-linear sigma model proposed by Finkelstein for interacting and disordered electronic systems. Spin rotation symmetry, present in the original saddle point solution, is spontaneously broken at one-loop, as in the Coleman-Weinberg mechanism. The new solution is singular in both the disorder and triplet interaction strengths, and it also explicitly demonstrates that a non-trivial ferromagnetic state appears in a theory where the disorder average is carried out from the outset.

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Claudio Chamon, Eduardo R. Mucciolo. 2000-06-19. Non-perturbative saddle point for the effective action of disordered and interacting electrons in 2D. https://doi.org/10.1103/physrevlett.85.5607

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