[quantum-info] PIQuDos seminar Wed March 4: Nengkun Yu

[Gus Gutoski]

Please join us on Wednesday, March 4 at 4pm in the Time room for a
quantum information seminar by Nengkun Yu.

Separability of Bosonic Systems

We study the separability of quantum states in bosonic system. Our
main tool here is the "separability witnesses", and a connection
between "separability witnesses" and a new kind of positivity of
matrices--- "Power Positive Matrices" is drawn. Such connection is
employed to demonstrate that multi-qubit quantum states with Dicke
states being its eigenvectors is separable if and only if two related
Hankel matrices are positive semidefinite. By employing this
criterion, we are able to show that such state is separable if and
only if it's partial transpose is non-negative, which confirms the
conjecture in [Wolfe, Yelin, Phys. Rev. Lett. (2014)]. Then, we
present a class of bosonic states in d⊗d system such that for general
d, determine its separabilityNP-hard although verifiable conditions
for separability is easily derived in case d=3,4.