scholarly journals Purification of two-qubit mixed states

2002 ◽  
Vol 2 (5) ◽  
pp. 348-354
Author(s):  
E. Jan\'e
Keyword(s):  
Qubit State ◽  
Entangled State ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Mixed States ◽  
Classical Communication ◽  
Maximally Entangled State ◽  
Optimal Protocol ◽  
Necessary And Sufficient

We find the necessary and sufficient condition under which two two-qubit mixed states can be purified into a pure maximally entangled state by local operations and classical communication. The optimal protocol for such transformation is obtained. This result leads to a necessary and sufficient condition for the exact purification of $n$ copies of a two-qubit state.

Horodeckis criterion of separability of mixed states in von Neumann and C*-algebras

2014 ◽  
Vol 17 (04) ◽  
pp. 1450028 ◽  
Author(s):  
Marek Miller ◽  
Robert Olkiewicz
Keyword(s):  
Quantum Systems ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Mixed States ◽  
Von Neumann ◽  
C Algebras ◽  
Necessary And Sufficient

The Horodeckis necessary and sufficient condition of separability of mixed states is generalized to arbitrary composite quantum systems.

Quantum correlation based on weak measurements

2017 ◽  
Vol 15 (06) ◽  
pp. 1750041 ◽  
Author(s):  
Yangyang Wang ◽  
Jinchuan Hou ◽  
Xiaofei Qi
Keyword(s):  
Pure State ◽  
Quantum Correlation ◽  
Qubit State ◽  
Sufficient Condition ◽  
Product State ◽  
Necessary And Sufficient Condition ◽  
Weak Measurements ◽  
Werner States ◽  
Necessary And Sufficient ◽  
Isotropic States

A quantum correlation [Formula: see text] based on weak measurements for bipartite systems is introduced. It is shown that the product states do not contain this quantum correlation. Also, the necessary and sufficient condition for any two-qubit state becoming a product state is obtained. The quantum correlation [Formula: see text] and other quantum correlation for two-qubit entangled pure state, Werner states and isotropic states are compared.

Entanglement transformations of pure Gaussian states

2003 ◽  
Vol 3 (3) ◽  
pp. 211-233
Author(s):  
G. Giedke ◽  
J. Eisert ◽  
J.I. Cirac ◽  
M.B. Plenio
Keyword(s):  
Phase Shifts ◽  
Gaussian State ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Optical Elements ◽  
Classical Communication ◽  
Gaussian States ◽  
Beam Splitters ◽  
Pure States ◽  
Necessary And Sufficient

We present a theory of entanglement transformations of Gaussian pure states with local Gaussian operations and classical communication. This is the experimentally accessible set of operations that can be realized with optical elements such as beam splitters, phase shifts and squeezers, together with homodyne measurements. We provide a simple necessary and sufficient condition for the possibility to transform a pure bipartite Gaussian state into another one. We contrast our criterion with what is possible if general local operations are available.

A GENERAL METHOD TO FIND PROPER CHANNEL FOR THREE-QUBIT STATE TELEPORTATION

2009 ◽  
Vol 07 (05) ◽  
pp. 927-933 ◽  
Author(s):  
XIU-LAO TIAN ◽  
XIAO-QIANG XI
Keyword(s):  
Qubit State ◽  
Tensor Analysis ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Trace Back ◽  
Bell Basis ◽  
Necessary And Sufficient ◽  
General Method

Based on tensor analysis and Bell basis measurement, we propose a general method to find proper channel for successful teleportation of an unknown three-qubit state. Instead of starting from "the proper channel" as that of the previous work, we begin from the successful teleportation then trace back to find which channel is proper and why it is proper for successful teleportation. At last, we give the necessary and sufficient condition for three-qubit perfect teleportation. This condition can guide us to design the corresponding channel for realizing the teleportation. Furthermore, the description of teleporting process with the help of tensor analysis is more compact and clear. Our method can also be generalized to find the channel for N-qubit successful teleportation.

A Proposed Framework Emphasizing Auditor Reliability over Auditor Independence

2003 ◽  
Vol 17 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Mark H. Taylor ◽  
F. Todd DeZoort ◽  
Edward Munn ◽  
Martha Wetterhall Thomas
Keyword(s):  
Public Interest ◽  
Auditor Independence ◽  
Public Confidence ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Accounting Profession ◽  
The Public ◽  
Necessary And Sufficient

This paper introduces an auditor reliability framework that repositions the role of auditor independence in the accounting profession. The framework is motivated in part by widespread confusion about independence and the auditing profession's continuing problems with managing independence and inspiring public confidence. We use philosophical, theoretical, and professional arguments to argue that the public interest will be best served by reprioritizing professional and ethical objectives to establish reliability in fact and appearance as the cornerstone of the profession, rather than relationship-based independence in fact and appearance. This revised framework requires three foundation elements to control subjectivity in auditors' judgments and decisions: independence, integrity, and expertise. Each element is a necessary but not sufficient condition for maximizing objectivity. Objectivity, in turn, is a necessary and sufficient condition for achieving and maintaining reliability in fact and appearance.

The Power of Public Positions

2018 ◽  
Author(s):  
Thomas Sinclair
Keyword(s):  
Detailed Analysis ◽  
Political Authority ◽  
The State ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
State Institutions ◽  
State Of Nature ◽  
Necessary And Sufficient

The Kantian account of political authority holds that the state is a necessary and sufficient condition of our freedom. We cannot be free outside the state, Kantians argue, because any attempt to have the “acquired rights” necessary for our freedom implicates us in objectionable relations of dependence on private judgment. Only in the state can this problem be overcome. But it is not clear how mere institutions could make the necessary difference, and contemporary Kantians have not offered compelling explanations. A detailed analysis is presented of the problems Kantians identify with the state of nature and the objections they face in claiming that the state overcomes them. A response is sketched on behalf of Kantians. The key idea is that under state institutions, a person can make claims of acquired right without presupposing that she is by nature exceptional in her capacity to bind others.

Sign in / Sign up

Export Citation Format

Share Document