Generation of entanglement in quantum parametric oscillators using phase control.
The control of quantum entanglement in systems in contact with environment plays an important role in information processing, cryptography and quantum computing. However, interactions with the environment, even when very weak, entail decoherence in the system with consequent loss of entanglement. Here we consider a system of two coupled oscillators in contact with a common heat bath and with a time dependent oscillation frequency. The possibility to control the entanglement of the oscillators by means of an external sinusoidal perturbation applied to the oscillation frequency has been theoretically explored. We demonstrate that the oscillators become entangled exactly in the region where the classical counterpart is unstable, otherwise when the classical system is stable, entanglement is not possible. Therefore, we can control the entanglement swapping from stable to unstable regions by adjusting amplitude and phase of our external controller. We also show that the entanglement rate is approximately proportional to the real part of the Floquet coefficient of the classical counterpart of the oscillators. Our results have the intriguing peculiarity of manipulating quantum information operating on a classical system.
Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas, Unicamp 13083-970, Campinas, São Paulo, Brazil.
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Gonzalez-Henao
1] Istituto Nazionale di Ottica-CNR Largo E. Fermi 6, 50125 Firenze, Italy [2] Dipartimento di Scienze della Terra - Università degli Studi di Firenze Via G. La Pira 4, Firenze, Italy.
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Pugliese
Istituto Nazionale di Ottica-CNR Largo E. Fermi 6, 50125 Firenze, Italy.
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Euzzor
Istituto Nazionale di Ottica-CNR Largo E. Fermi 6, 50125 Firenze, Italy.
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Abdalah
Istituto Nazionale di Ottica-CNR Largo E. Fermi 6, 50125 Firenze, Italy.
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Meucci
Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas, Unicamp 13083-970, Campinas, São Paulo, Brazil.
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Roversi