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Exact-exchange density-functional theory for quasi-two-dimensional electron gases

F. A. Reboredo·C. R. Proetto
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Abstract

A simple exact-exchange density-functional method for a quasi-two-dimensional electron gas with variable density is presented. An analytical expression for the exact-exchange potential with only one occupied subband is provided, without approximations. When more subbands are occupied the exact-exchange potential is obtained numerically. The theory shows that, in contradiction with LDA, the exact-exchange potential exhibits discontinuities and the system suffers a zero-temperature first-order transition each time a subband is occupied. Results suggesting that the translational symmetry might be spontaneously broken at zero temperature are presented. An extension of the theory to finite temperatures allows to describe a drop in the intersubband spacing in good quantitative agreement with recent experiments.

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F. A. Reboredo, C. R. Proetto. 2002-11-16. Exact-exchange density-functional theory for quasi-two-dimensional electron gases. https://doi.org/10.1103/physrevb.67.115325

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