Speaker
Carlos L. Benavides-Riveros
(Martin-Luther-Universität Halle-Wittenberg)
Description
The possible compatibility of density matrices for single-party subsystems is described by linear constraints on their respective spectra. Whenever some of those quantum marginal constraints are saturated, the total quantum state has a specific, simplified structure. We prove that these remarkable global implications of extremal local information are stable, i.e. they hold approximately for spectra close to the boundary of the allowed region. Application of this general result to fermionic quantum systems allows us to characterize natural extensions of the Hartree-Fock ansatz and to quantify their accuracy by resorting to one-particle information, only.
Authors
Carlos L. Benavides-Riveros
(Martin-Luther-Universität Halle-Wittenberg)
Christian Schilling
(University of Oxford)
Péter Vrana
(Department of Geometry, Budapest University of Technology and Economics, Budapest, Hungary)
