Published June 2013 | Version v1
Journal article

On an extension problem for density matrices

  • 1. Department of Mathematics, Hill Center, Rutgers University, 110 Frelinghuysen Road, Piscataway, New Jersey 08854-8019 (United States)
  • 2. Departments of Mathematics and Physics, Hill Center, Rutgers University, 110 Frelinghuysen Road, Piscataway, New Jersey 08854-8019 (United States)
  • 3. Departments of Mathematics and Physics, Jadwin Hall, Princeton University, Washington Road, Princeton, New Jersey 08544-0001 (United States)

Description

We investigate the problem of the existence of a density matrix ρ123 on a Hilbert space H1⊗H2⊗H3 with given partial traces ρ12= Tr3 ρ123 and ρ23= Tr1 ρ123. While we do not solve this problem completely, we offer partial results in the form of some necessary and some sufficient conditions on ρ12 and ρ23. The quantum case differs markedly from the classical (commutative) case, where the obvious necessary compatibility condition suffices, namely, Tr1 ρ12= Tr3ρ23.

Additional details

Identifiers

Publishing Information

Journal Title
Journal of Mathematical Physics
Journal Volume
54
Journal Issue
6
Journal Page Range
p. 062103-062103.9
ISSN
0022-2488
CODEN
JMAPAQ

INIS

Country of Publication
United States
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
44117513
Subject category
S71: CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS;
Descriptors DEI
ALGEBRA; COMPATIBILITY; DENSITY MATRIX; HILBERT SPACE
Descriptors DEC
BANACH SPACE; MATHEMATICAL SPACE; MATHEMATICS; MATRICES; SPACE

Optional Information

Notes
(c) 2013 AIP Publishing LLC