Positive extensions of automorphisms of spin factors

1983 ◽  
Vol 94 (1-2) ◽  
pp. 71-77 ◽  
Author(s):  
A. Guyan Robertson
Keyword(s):  
Positive Cone ◽  
Complex Matrix ◽  
Matrix Algebras ◽  
Spin Factor ◽  
Finite Dimensional ◽  
Linear Maps ◽  
Positive Linear Maps ◽  
Extreme Rays ◽  
Positive Extensions

SynopsisA spin factor is a JW-factor of type I2. It is shown that certain automorphisms of finite dimensional spin factors extend to extremal positive linear maps on complex matrix algebras which are not decomposable, and hence, do not preserve extreme rays of the positive cone.

scholarly journals FACIAL STRUCTURES FOR VARIOUS NOTIONS OF POSITIVITY AND APPLICATIONS TO THE THEORY OF ENTANGLEMENT

2013 ◽  
Vol 25 (02) ◽  
pp. 1330002 ◽  
Author(s):  
SEUNG-HYEOK KYE
Keyword(s):  
Convex Cones ◽  
Edge States ◽  
Completely Positive ◽  
Matrix Algebras ◽  
Linear Maps ◽  
Entanglement Witnesses ◽  
Positive Linear Maps

In this expository note, we explain facial structures for the convex cones consisting of positive linear maps, completely positive linear maps, and decomposable positive linear maps between matrix algebras, respectively. These will be applied to study the notions of entangled edge states with positive partial transposes and optimality of entanglement witnesses.

Duality for positive linear maps in matrix algebras

2000 ◽  
Vol 86 (1) ◽  
pp. 130 ◽  
Author(s):  
Myoung-Hoe Eom ◽  
Seung-Hyeok Kye
Keyword(s):  
Matrix Algebras ◽  
Linear Maps ◽  
Positive Linear Maps

scholarly journals Exposedness of Choi-Type Entanglement Witnesses and Applications to Lengths of Separable States

2013 ◽  
Vol 20 (04) ◽  
pp. 1350012 ◽  
Author(s):  
Kil-Chan Ha ◽  
Seung-Hyeok Kye
Keyword(s):  
Large Class ◽  
Separable State ◽  
Matrix Algebras ◽  
Separable States ◽  
Linear Maps ◽  
Entanglement Witnesses ◽  
Positive Linear Maps

We present a large class of indecomposable exposed positive linear maps between 3 × 3 matrix algebras. We also construct two-qutrit separable states with lengths ten in the interior of their dual faces. With these examples, we show that the length of a separable state may decrease strictly when we mix it with another separable state.

Facial Structures for the Positive Linear Maps Between Matrix Algebras

1996 ◽  
Vol 39 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Seung-Hyeok Kye
Keyword(s):  
Complete Lattice ◽  
Matrix Algebra ◽  
Convex Set ◽  
Matrix Algebras ◽  
Linear Maps ◽  
The Matrix ◽  
Positive Linear Maps

AbstractLet denote the convex set of all positive linear maps from the matrix algebra Mn(ℂ) into itself. We construct a join homomorphism from the complete lattice of all faces of into the complete lattice of all join homomorphisms between the lattice of all subspaces of ℂn . We also characterize all maximal faces of .

Sign in / Sign up

Export Citation Format

Share Document