TUTCRIS - Tampereen teknillinen yliopisto

TUTCRIS

Hermitian one-particle density matrix through a semiclassical gradient expansion

Tutkimustuotosvertaisarvioitu

Yksityiskohdat

AlkuperäiskieliEnglanti
Artikkeli015205
JulkaisuJournal of Physics A: Mathematical and Theoretical
Vuosikerta49
Numero1
DOI - pysyväislinkit
TilaJulkaistu - 9 joulukuuta 2015
OKM-julkaisutyyppiA1 Alkuperäisartikkeli

Tiivistelmä

We carry out the semiclassical expansion of the one-particle density matrix up to the second order in h. We use the method of Grammaticos and Voros based on the Wigner transform of operators. We show that the resulting density matrix is Hermitian and idempotent in contrast with the well-known result of the semiclassical Kirzhnits expansion. Our density matrix leads to the same particle density and kinetic energy density as in the literature, and it satisfies the consistency criterion of the Euler equation. The derived Hermitian density matrix clarifies the ambiguity in the usefulness of gradient expansion approximations and might reignite the development of density functionals with semiclassical methods.