TY - JOUR

T1 - Time-dependent occupation numbers in reduced-density-matrix-functional theory

T2 - Application to an interacting Landau-Zener model

AU - Requist, Ryan

AU - Pankratov, Oleg

PY - 2011/5/18

Y1 - 2011/5/18

N2 - We prove that if the two-body terms in the equation of motion for the one-body reduced density matrix are approximated by ground-state functionals, the eigenvalues of the one-body reduced density matrix (occupation numbers) remain constant in time. This deficiency is related to the inability of such an approximation to account for relative phases in the two-body reduced density matrix. We derive an exact differential equation giving the functional dependence of these phases in an interacting Landau-Zener model and study their behavior in short- and long-time regimes. The phases undergo resonances whenever the occupation numbers approach the boundaries of the interval [0,1]. In the long-time regime, the occupation numbers display correlation-induced oscillations and the memory dependence of the functionals assumes a simple form.

AB - We prove that if the two-body terms in the equation of motion for the one-body reduced density matrix are approximated by ground-state functionals, the eigenvalues of the one-body reduced density matrix (occupation numbers) remain constant in time. This deficiency is related to the inability of such an approximation to account for relative phases in the two-body reduced density matrix. We derive an exact differential equation giving the functional dependence of these phases in an interacting Landau-Zener model and study their behavior in short- and long-time regimes. The phases undergo resonances whenever the occupation numbers approach the boundaries of the interval [0,1]. In the long-time regime, the occupation numbers display correlation-induced oscillations and the memory dependence of the functionals assumes a simple form.

UR - http://www.scopus.com/inward/record.url?scp=79961049327&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.83.052510

DO - 10.1103/PhysRevA.83.052510

M3 - Article

AN - SCOPUS:79961049327

SN - 1050-2947

VL - 83

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

IS - 5

M1 - 052510

ER -