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One-dimensional electron gas interacting with a Heisenberg spin-1/2 chain

Oron Zachar·Alexei M. Tsvelik
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Abstract

We analyse a model of a one-dimensional electron gas interacting with an antiferromagnetic Heisenberg spin-1/2 chain via the spin exchange interactions. Using a solution at a special limit, we characterize the gapless modes of the spin gap fixed point at weak coupling $ J_{K}\ll J_{H},E_{F} $. we show that the only gapless pairing mode with divergent susceptibility is a composite odd-parity odd-frequency singlet pairing order parameter, while the ordinary BCS even-parity singlet pairing mode is incoherent. For 2-leg ladder systems, we note that it is possible to have a range of doping where the chemical potential cuts only the anti-bonding band while the bonding band remains half-filled. We propose that, in such a state, the 2-leg ladder is effectively realizing the one-dimensional Kondo-Heisenberg model.

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Oron Zachar, Alexei M. Tsvelik. 2001-05-03. One-dimensional electron gas interacting with a Heisenberg spin-1/2 chain. https://doi.org/10.1103/physrevb.64.033103

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