Composition of PPT maps

Autor: Vern I. Paulsen, Nicholas A. Manor, Matthew Kennedy
Rok vydání: 2018
Předmět:
Zdroj: Quantum Information and Computation. 18:472-480
ISSN: 1533-7146
Popis: M. Christandl conjectured that the composition of any trace preserving PPT map with itself is entanglement breaking. We prove that Christandl's conjecture holds asymptotically by showing that the distance between the iterates of any unital or trace preserving PPT map and the set of entanglement breaking maps tends to zero. Finally, for every graph we define a one-parameter family of maps on matrices and determine the least value of the parameter such that the map is variously, positive, completely positive, PPT and entanglement breaking in terms of properties of the graph. Our estimates are sharp enough to conclude that Christandl's conjecture holds for these families.
Comment: 10 pages
Databáze: OpenAIRE