8 papers
A partial-trace matrix inequality and Werner-state distillability
Zhiwei Song, Lin Chen
Motivated by the equivalent partial-trace formulations of Werner-state distillability [P. Costa Rico, Lett. Math. Phys. 115, 47 (2025); S.-Y. Qi et al., Phys. Rev. A 110, 012406 (2…
A counterexample to the strong spin alignment conjecture
Zhiwei Song, Lin Chen
The spin alignment conjecture was originally formulated in connection with the additivity of coherent information for a class of quantum channels known as platypus channels. Recent…
Extreme points of absolutely PPT states with exactly three distinct eigenvalues
Nalan Wang, Lin Chen, Zhiwei Song
Whether the sets of absolutely separable (AS) and absolutely two-qutrit positive-partial-transpose (AP) states are the same has been an open problem in entanglement theory for deca…
Spectral characterizations of entanglement witnesses
Zhiwei Song, Lin Chen
We present a systematic investigation of the spectral properties of entanglement witnesses (EWs). Specifically, we analyze the infimum and supremum of the largest eigenvalue, the s…
Multipartite entangling power by von Neumann entropy
Xinyu Qiu, Zhiwei Song, Lin Chen
Quantifying the entanglement generation of a multipartite unitary operation is a key problem in quantum information processing. We introduce the definition of multipartite entangli…
On the extreme points of sets of absolulely separable and PPT states
Zhiwei Song, Lin Chen
The absolutely separable (resp. PPT) states remain separable (resp. positive partial transpose) under any global unitary operation. We present a compact form of the extreme points…