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Instanton calculation of the density of states of disordered Peierls chains

Maxim Mostovoy·Jasper Knoester
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Abstract

We use the optimal fluctuation method to find the density of electron states inside the pseudogap in disordered Peierls chains. The electrons are described by the one-dimensional Dirac Hamiltonian with randomly varying mass (the Fluctuating Gap Model). We establish a relation between the disorder average in this model and the quantum-mechanical average for a certain double-well problem. We show that the optimal disorder fluctuation, which has the form of a soliton-antisoliton pair, corresponds to the instanton trajectory in the double-well problem. We use the instanton method developed for the double-well problem to find the contribution to the density of states from disorder realizations close to the optimal fluctuation.

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Maxim Mostovoy, Jasper Knoester. 1998-05-07. Instanton calculation of the density of states of disordered Peierls chains. https://doi.org/10.1142/s0217979299001594

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