Mainz 2017 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 16: Quantum Information: Concepts and Methods III
Q 16.4: Talk
Tuesday, March 7, 2017, 11:45–12:00, P 2
Implications of (quasi)extremal local information for the many-body wave function — •Carlos L. Benavides-Riveros1, Christian Schilling2, and Peter Vrana3 — 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle, Germany — 2Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom — 3Department of Geometry, Budapest University of Technology and Economics, Egry József u. 1., 1111 Budapest, Hungary
The possible compatibility of given density matrices for single site subsystems of a multipartite quantum system 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 propose natural extensions of the Hartree-Fock and Kohn-Sham ansätze based on the corresponding generalized Pauli constraints. This ``Muliticonfigurational Self-Consistent Field''-ansatz is tested for a simple model allowing us to reconstruct about 99.5% of the correlation energy.