TY - JOUR

T1 - Dynamics beyond completely positive maps

T2 - Some properties and applications

AU - Carteret, Hilary A.

AU - Terno, Daniel R.

AU - Zyczkowski, Karol

N1 - Hilary A. Carteret, Daniel R. Terno, and Karol Zyczkowski, Physical review A, Vol. 77, Iss. 4, 042113 (2008). Copyright 2008 by the American Physical Society. The original article can be found at http://link.aps.org/doi/10.1103/PhysRevA.77.042113

PY - 2008/4/18

Y1 - 2008/4/18

N2 - Maps that are not completely positive (CP) are often useful to describe the dynamics of open systems. An apparent violation of complete positivity can occur because there are prior correlations of the principal system with the environment, or if the applied transformation is correlated with the state of the system. We provide a physically motivated definition of accessible non-CP maps and derive two necessary conditions for a map to be accessible. We also show that entanglement between the system and the environment is not necessary to generate a non-CP dynamics. We describe two simple approximations that may be sufficient for some problems in process tomography, and then outline what these methods may be able to tell us in other situations where non-CP dynamics naturally arise.

AB - Maps that are not completely positive (CP) are often useful to describe the dynamics of open systems. An apparent violation of complete positivity can occur because there are prior correlations of the principal system with the environment, or if the applied transformation is correlated with the state of the system. We provide a physically motivated definition of accessible non-CP maps and derive two necessary conditions for a map to be accessible. We also show that entanglement between the system and the environment is not necessary to generate a non-CP dynamics. We describe two simple approximations that may be sufficient for some problems in process tomography, and then outline what these methods may be able to tell us in other situations where non-CP dynamics naturally arise.

UR - http://www.scopus.com/inward/record.url?scp=42449114470&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.77.042113

DO - 10.1103/PhysRevA.77.042113

M3 - Article

AN - SCOPUS:42449114470

VL - 77

SP - 1

EP - 8

JO - Physical Review A: covering atomic, molecular, and optical physics and quantum information

JF - Physical Review A: covering atomic, molecular, and optical physics and quantum information

SN - 2469-9926

IS - 4

M1 - 042113

ER -