Relaxation effects on exciton maximally entangled states in quantum dots

Celestino Creatore, Richard Brierley, R. T. Phillips +2 more

Ferney J. Rodríguez, Luis Quiroga, Neil F. Johnson

We report on exciton-acoustic-phonon coupling effects on the generation of exciton maximally entangled states in N = 2 and 3 quantum dot systems. In particular, we address the question of the combined effect of laser pulses, appropriate for generating Bell and Greenberger-Horne-Zeilinger entangled states, together with decoherence mechanisms as provided by a phonon reservoir. By solving numerically the master equation for the optically driven exciton–phonon kinetics, we show that the generation of maximally entangled exciton states is preserved over a reasonable parameter window.

Man Shen, Jian-Jun Liu

Using the one-dimensional effective potential method, we theoretically study the properties of an exciton in vertically coupled quantum dots (VCQDs) under the influence of an applied magnetic field. The ground state transition energies of the heavy-hole exciton are calculated in a single quantum dot and in VCQDs, respectively. Our results are in good agreement with those of experiments. In symmetrical VCQDs, the entanglement of the exciton state monotonously increases with increasing barrier width, and can even attain the value of the maximally entangled state. When the symmetry of the VCQDs is broken, the entanglement of the exciton state almost entirely breaks down under the combined influences of tunneling and the Coulomb interactions.

Emmanuel Paspalakis, Andreas Terzis

Yu-xi Liu, Şahin Kaya Özdemir, Masato Koashi +1 more

The dynamics of the entanglement for coherent excitonic states in the system of two, coupled, large semiconductor quantum dots ${(R/a}_{B}\ensuremath{\gg}1)$ mediated by a single-mode cavity field is investigated. Maximally entangled coherent excitonic states can be generated by cavity field initially prepared in odd coherent state. The entanglement of the excitonic coherent states between two dots reaches maximum when no photon is present in the cavity. The effects of the zero-temperature environment on the entanglement of excitonic coherent state are also studied using the concurrence for two subsystems of the excitons.

M. Bayer, G. Ortner, A. V. Larionov +7 more