Eur. Phys. J. D 62, 273-277 (2011)
https://doi.org/10.1140/epjd/e2011-10450-8

Entanglement witnesses for d ⊗ d systems and new classes of entangled qudit states

Institute of Physics, Nicolaus Copernicus University, Grudziądzka 5/7, 87100 Toruń, Poland

^a e-mail: darch@fizyka.umk.pl

Received: 11 August 2010
Received in final form: 13 December 2010
Published online: 18 March 2011

Abstract

We provide a new class of entanglement witnesses for d ⊗ d systems (two qudits). Our construction generalizes the one proposed recently by Jafarizadeh et al. for d = 3 and d = 4 on the basis of semidefinite linear programming. Moreover, we provide a new class of PPT entangled states detected by our witnesses which generalizes well known family of states constructed by Horodecki et al. for d = 3.