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Related papers: Differential geometry of density states

200 papers

The shape space of k labelled points on a plane can be identified with the space of pure quantum states of dimension k-2. Hence, the machinery of quantum mechanics can be applied to the statistical analysis of planar configurations of…

Quantum Physics · Physics 2009-11-10 Dorje C. Brody

We construct a space of quantum states and an algebra of quantum observables, over the set of all metrics of arbitrary but fixed signature, defined on a manifold. The construction is diffeomorphism invariant, and unique up to natural…

Mathematical Physics · Physics 2021-06-22 Andrzej Okolow

A recently proposed convolution technique for the calculation of local density of states is described more thouroughly and new results of its application are presented. For separable systems the exposed method allows to construct the ldos…

Condensed Matter · Physics 2009-11-07 A. Losev , S. Vlaev

We derive necessary and sufficient conditions for a group of density matrices to characterize what different people may know about one and the same physical system.

Quantum Physics · Physics 2009-11-07 Todd A. Brun , J. Finkelstein , N. David Mermin

An operator generalisation of the notion of geometric phase has been recently proposed purely based on physical grounds. Here we provide a mathematical foundation for its existence, while uncovering new geometrical structures in quantum…

Quantum Physics · Physics 2023-12-25 Vivek M. Vyas

Two-dimensional topological states of matter offer a route to quantum computation that would be topologically protected against the nemesis of the quantum circuit model: decoherence. Research groups in industry, government and academic…

Mathematical Physics · Physics 2016-05-04 Eric C. Rowell

This paper is devoted to the description of the evolution of states of quantum many-particle systems within the framework of a one-particle density operator, which enables to construct the kinetic equations in scaling limits in the presence…

Mathematical Physics · Physics 2012-09-07 V. I. Gerasimenko , Zh. A. Tsvir

It is argued that spectral features of quantal systems with random interactions can be given a geometric interpretation. This conjecture is investigated in the context of two simple models: a system of randomly interacting d bosons and one…

Nuclear Theory · Physics 2009-11-10 P. Chau Huu-Tai , A. Frank , N. A. Smirnova , P. Van Isacker

We analyze the geometric phase for an open quantum system when computed by resorting to a stochastic unravelling of the reduced density matrix (quantum jump approach or stochastic Schrodienger equations). We show that the resulting phase…

Quantum Physics · Physics 2007-05-23 A. Bassi , E. Ippoliti

We propose a detailed study of the geometric entanglement properties of pure symmetric N-qubit states, focusing more particularly on the identification of symmetric states with a high geometric entanglement and how their entanglement…

Quantum Physics · Physics 2010-07-01 J. Martin , O. Giraud , P. A. Braun , D. Braun , T. Bastin

We discuss the concept of how entanglement changes with respect to different factorizations of the total algebra which describes the quantum states. Depending on the considered factorization a quantum state appears either entangled or…

Quantum Physics · Physics 2011-11-15 Walter Thirring , Reinhold A. Bertlmann , Philipp Köhler , Heide Narnhofer

A parametrization of density operators for bipartite quantum systems is proposed. It is based on the particular parametrization of the unitary group found recently by Jarlskog. It is expected that this parametrization will find interesting…

Quantum Physics · Physics 2009-10-20 Erwin Bruening , Dariusz Chruscinski , Francesco Petruccione

We elaborate on a geometric characterization of the electromagnetic properties of matter. A fundamental complex quantity, z_{L}, is introduced to study the localization properties of extended quantum systems. z_L, which allows us to…

Condensed Matter · Physics 2015-06-25 G. Ortiz , A. A. Aligia

Off-diagonal geometric phases have been developed in order to provide information of the geometry of paths that connect noninterfering quantal states. We propose a kinematic approach to off-diagonal geometric phases for pure and mixed…

Quantum Physics · Physics 2016-08-16 D. M. Tong , Erik Sjöqvist , Stefan Filipp , L. C. Kwek , C. H. Oh

Studying the geometry of sets appearing in various problems of quantum information helps in understanding different parts of the theory. It is thus worthwhile to approach quantum mechanics from the angle of geometry -- this has already…

Quantum Physics · Physics 2023-03-15 Konrad Szymański

Probabilistic quantum state transformations can be characterized by the degree of state separation they provide. This, in turn, sets limits on the success rate of these transformations. We consider optimum state separation of two known pure…

Quantum Physics · Physics 2016-01-20 Emilio Bagan , Vadim Yerokhin , Andi Shehu , Edgar Feldman , Janos A. Bergou

We explore the relation between quantum geometry in non-Hermitian systems and physically measurable phenomena. We highlight various situations in which the behavior of a non-Hermitian system is best understood in terms of quantum geometry,…

Quantum Physics · Physics 2026-03-16 Anton Montag , Tomoki Ozawa

The coherence of an individual quantum state can be meaningfully discussed only when referring to a preferred basis. This arbitrariness can however be lifted when considering sets of quantum states. Here we introduce the concept of set…

Quantum Physics · Physics 2021-06-08 Sébastien Designolle , Roope Uola , Kimmo Luoma , Nicolas Brunner

Motivated by research on contraction analysis and incremental stability/stabilizability the study of 'differential properties' has attracted increasing attention lately. Previously lifts of functions and vector fields to the tangent bundle…

Optimization and Control · Mathematics 2015-04-10 Arjan van der Schaft

The operational meaning of coherence measure lies at very heart of the coherence theory. In this paper, we provide an operational interpretation for geometric coherence, by proving that the geometric coherence of a quantum state is equal to…

Quantum Physics · Physics 2018-09-26 Chunhe Xiong , Junde Wu