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Exchange Frequencies in the 2d Wigner crystal

B. Bernu·Ladir Candido·D. M. Ceperley
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Abstract

Using Path Integral Monte Carlo we have calculated exchange frequencies as electrons undergo ring exchanges in a ``clean'' 2d Wigner crystal as a function of density. The results show agreement with WKB calculations at very low density, but show a more rapid increase with density near melting. Remarkably, the exchange Hamiltonian closely resembles the measured exchanges in 2d He. Using the resulting multi-spin exchange model we find the spin Hamiltonian for r_s \leq 175 \pm 10 is a frustrated antiferromagnetic; its likely ground state is a spin liquid. For lower density the ground state will be ferromagnetic.

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B. Bernu, Ladir Candido, D. M. Ceperley. 2000-08-03. Exchange Frequencies in the 2d Wigner crystal. https://doi.org/10.1103/physrevlett.86.870

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