## 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.

Original language | English |
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Article number | 115325 |

Pages (from-to) | 1153251-1153255 |

Number of pages | 5 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 67 |

Issue number | 11 |

State | Published - Mar 2003 |

Externally published | Yes |