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Thermal melting of density waves on the square lattice

Adrian Del Maestro·Subir Sachdev
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Abstract

We present the theory of the effect of thermal fluctuations on commensurate "p x p" density wave ordering on the square lattice (p >= 3, integer). For the case in which this order is lost by a second order transition, we argue that the adjacent state is generically an incommensurate striped state, with commensurate p-periodic long range order along one direction, and incommensurate quasi-long-range order along the orthogonal direction. We also present the routes by which the fully disordered high temperature state can be reached. For p=4, and at special commensurate densities, the "4 x 4" commensurate state can melt directly into the disordered state via a self-dual critical point with non-universal exponents.

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Adrian Del Maestro, Subir Sachdev. 2004-12-19. Thermal melting of density waves on the square lattice. https://doi.org/10.1103/physrevb.71.184511

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