Constraints between concurrence and polarization for mixed states subjected to open system dynamics

• Autor: Montenegro La Torre, Carlos Renzo Misael
• Formato: tesis de maestría
• Fecha de Publicación: 2022
• Institución: Pontificia Universidad Católica del Perú
• Repositorio: PUCP-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.pucp.edu.pe:20.500.14657/193792
• Enlace del recurso: http://hdl.handle.net/20.500.12404/25024
• Nivel de acceso: acceso abierto
• Materia: Polarización (Física nuclear); Topología; Teoría cuántica; https://purl.org/pe-repo/ocde/ford#1.03.00

Entanglement and polarization are mutually constrained by the relationship C2 + P2 = 1, which engages concurrence (C) of a pure, two-qubit state and the degree of polarization (P) of either of its two subsystems. How the above constraint generalizes for mixed states, is an open question. We address mixed, two-qubit states of the X type, i.e., those whose density matrix has nonzero elements only in the two main diagonals. We focus on mixed states that arise out of a pure, two-qubit state that is subjected to either the amplitude damping channel or the depolarizing channel. We derive alternative constraints for concurrence and polarization and test them experimentally with polarization-entangled photons. We argue that our theoretical results hold also for classical light, whenever two binary degrees of freedom can be entangled.