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Title: Nonequilibrium thermal effects on exciton time correlations in coupled semiconductor quantum dots

Theoretical guides to test 'macroscopic realism' in solid-state systems under quantum control are highly desirable. Here, we report on the evolution of a Leggett-Garg inequality (LGI), a combination of two-time correlations, in an out-of-equilibrium set up consisting of two interacting excitons confined in separate semiconductor quantum dots which are coupled to independent baths at different temperatures (T{sub 1} ≠ T{sub 2}). In a Markovian steady-state situation we found a rich variety of dynamical behaviors in different sectors of the average temperature (T{sub M} = (T{sub 1}+T{sub 2})/2) vs. coupling strength to the reservoirs (Γ) space parameter. For high T{sub M} and Γ values the LGI is not violated, as expected. However, by decreasing T{sub M} or Γ a sector of parameters appears where the LGI is violated at thermal equilibrium (T{sub 1} = T{sub 2}) and the violation starts decreasing when the system is moved out of the equilibrium. Surprisingly, at even lower T{sub M} values, for any Γ, there is an enhancement of the LGI violation by exposing the system to a temperature gradient, i.e. quantum correlations increase in a nonequilibrium thermal situation. Results on LGI violations in a steady-state regime are compared with other non-locality-dominated quantum correlation measurements, such asmore » concurrence and quantum discord, between the two excitons under similar temperature gradients.« less
Authors:
; ;  [1]
  1. Departamento de Física, Universidad de los Andes, AA 4976, Bogotá (Colombia)
Publication Date:
OSTI Identifier:
22261937
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1566; Journal Issue: 1; Conference: ICPS 2012: 31. international conference on the physics of semiconductors, Zurich (Switzerland), 29 Jul - 3 Aug 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; QUANTUM DOTS; SEMICONDUCTOR MATERIALS; SOLIDS; TEMPERATURE DEPENDENCE; TEMPERATURE GRADIENTS; THERMAL EQUILIBRIUM