scholarly journals Optimized maximum-confidence discrimination ofNmixed quantum states and application to symmetric states

2012 ◽  
Vol 85 (3) ◽  
Author(s):  
Ulrike Herzog
Keyword(s):  
Quantum States ◽  
Symmetric States

scholarly journals Entangled symmetric states and copositive matrices

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 561
Author(s):  
Carlo Marconi ◽  
Albert Aloy ◽  
Jordi Tura ◽  
Anna Sanpera
Keyword(s):  
Quantum States ◽  
Copositive Matrices ◽  
Entanglement Witnesses ◽  
Symmetric Quantum ◽  
Symmetric States ◽  
Odd Dimensions

Entanglement in symmetric quantum states and the theory of copositive matrices are intimately related concepts. For the simplest symmetric states, i.e., the diagonal symmetric (DS) states, it has been shown that there exists a correspondence between exceptional (non-exceptional) copositive matrices and non-decomposable (decomposable) Entanglement Witnesses (EWs). Here we show that EWs of symmetric, but not DS, states can also be constructed from extended copositive matrices, providing new examples of bound entangled symmetric states, together with their corresponding EWs, in arbitrary odd dimensions.

Optimal class-specific witnesses for three-qubit entanglement from Greenberger-Horne-Zeilinger symmetry

2013 ◽  
Vol 13 (3&4) ◽  
pp. 210-220
Author(s):  
Christopher Eltschka ◽  
Jens Siewert
Keyword(s):  
Ghz State ◽  
Quantum States ◽  
Point Of View ◽  
The Other ◽  
Mixed States ◽  
Other Hand ◽  
New Type ◽  
The One ◽  
Qubit States ◽  
Symmetric States

Recently, a new type of symmetry for three-qubit quantum states was introduced, the so-called Greenberger-Horne-Zeilinger (GHZ) symmetry. It includes the operations which leave the three-qubit standard GHZ state unchanged. This symmetry is powerful as it yields families of mixed states that are, on the one hand, complex enough from the physics point of view and, on the other hand, simple enough mathematically so that their properties can be characterized analytically. We show that by using the properties of GHZ-symmetric states it is straightforward to derive optimal witnesses for detecting class-specific entanglement in arbitrary three-qubit states.

Geometry of Quantum States

2006 ◽  
Author(s):  
Ingemar Bengtsson ◽  
Karol Zyczkowski
Keyword(s):  
Quantum States

Transport of quantum states of periodically driven systems

1990 ◽  
Vol 51 (8) ◽  
pp. 709-722 ◽  
Author(s):  
H.P. Breuer ◽  
K. Dietz ◽  
M. Holthaus
Keyword(s):  
Quantum States ◽  
Driven Systems ◽  
Periodically Driven

Quantum States & Processes

1994 ◽  
Vol 187 (Part_1) ◽  
pp. 156-156
Author(s):  
H.-J. Unger
Keyword(s):  
Quantum States

“Non-locality”

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
Quantum Entanglement ◽  
Quantum States ◽  
Entangled States ◽  
Entangled Quantum States ◽  
Action At A Distance ◽  
Insight Into ◽  
Non Locality

Quantum entanglement is popularly believed to give rise to spooky action at a distance of a kind that Einstein decisively rejected. Indeed, important recent experiments on systems assigned entangled states have been claimed to refute Einstein by exhibiting such spooky action. After reviewing two considerations in favor of this view I argue that quantum theory can be used to explain puzzling correlations correctly predicted by assignment of entangled quantum states with no such instantaneous action at a distance. We owe both considerations in favor of the view to arguments of John Bell. I present simplified forms of these arguments as well as a game that provides insight into the situation. The argument I give in response turns on a prescriptive view of quantum states that differs both from Dirac’s (as stated in Chapter 2) and Einstein’s.

Quantum optics with nitrogen-vacancy centres in diamond

2017 ◽  
Author(s):  
Yiwen Chu ◽  
Mikhail D. Lukin
Keyword(s):  
Optical Properties ◽  
Quantum Information ◽  
Solid State ◽  
Quantum Optics ◽  
Quantum States ◽  
Nitrogen Vacancy ◽  
Common Theme ◽  
External Effects ◽  
Promising Candidate ◽  
Optical Photons

A common theme in the implementation of quantum technologies involves addressing the seemingly contradictory needs for controllability and isolation from external effects. Undesirable effects of the environment must be minimized, while at the same time techniques and tools must be developed that enable interaction with the system in a controllable and well-defined manner. This chapter addresses several aspects of this theme with regard to a particularly promising candidate for developing applications in both metrology and quantum information, namely the nitrogen-vacancy (NV) centre in diamond. The chapter describes how the quantum states of NV centres can be manipulated, probed, and efficiently coupled with optical photons. It also discusses ways of tackling the challenges of controlling the optical properties of these emitters inside a complex solid state environment.

Quantum Theory

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Uncertainty Principle ◽  
Quantum Spin ◽  
Quantum States ◽  
Wave Functions ◽  
Symbolic Representations ◽  
Quantum Numbers ◽  
The Subject ◽  
Heisenberg's Uncertainty Principle

The subject of Chapter 8 is the fundamental principles of quantum theory, the abstract extension of quantum mechanics. Two of the entities explored are kets and operators, with kets being representations of quantum states as well as a source of wave functions. The quantum box and quantum spin kets are specified, as are the quantum numbers that identify them. Operators are introduced and defined in part as the symbolic representations of observable quantities such as position, momentum and quantum spin. Eigenvalues and eigenkets are defined and discussed, with the former identified as the possible outcomes of a measurement. Bras, the counterpart to kets, are introduced as the means of forming probability amplitudes from kets. Products of operators are examined, as is their role underpinning Heisenberg’s Uncertainty Principle. A variety of symbol manipulations are presented. How measurements are believed to collapse linear superpositions to one term of the sum is explored.

Sign in / Sign up

Export Citation Format

Share Document