306 research outputs found
Spontaneous Conversion from Virtual to Real Photons in the Ultrastrong Coupling Regime
We show that a spontaneous release of virtual photon pairs can occur in a
quantum optical system in the ultrastrong coupling regime. In this regime,
which is attracting interest both in semiconductor and superconducting systems,
the light-matter coupling rate {\Omega}R becomes comparable to the bare
resonance frequency of photons {\omega}0. In contrast to the dynamical Casimir
effect and other pair creation mechanisms, this phenomenon does not require
external forces or time dependent parameters in the Hamiltonian.Comment: To appear on Phys. Rev. Let
Entanglement Dynamics of Two Independent Cavity-Embedded Quantum Dots
We investigate the dynamical behavior of entanglement in a system made by two
solid-state emitters, as two quantum dots, embedded in two separated
micro-cavities. In these solid-state systems, in addition to the coupling with
the cavity mode, the emitter is coupled to a continuum of leaky modes providing
additional losses and it is also subject to a phonon-induced pure dephasing
mechanism. We model this physical configuration as a multipartite system
composed by two independent parts each containing a qubit embedded in a
single-mode cavity, exposed to cavity losses, spontaneous emission and pure
dephasing. We study the time evolution of entanglement of this multipartite
open system finally applying this theoretical framework to the case of
currently available solid-state quantum dots in micro-cavities.Comment: 10 pages, 4 figures, to appear in Topical Issue of Physica Scripta on
proceedings of CEWQO 201
Dynamics and extraction of quantum discord in a multipartite open system
We consider a multipartite system consisting of two noninteracting qubits
each embedded in a single-mode leaky cavity, in turn connected to an external
bosonic reservoir. Initially, we take the two qubits in an entangled state
while the cavities and the reservoirs have zero photons. We investigate, in
this six-partite quantum system, the transfer of quantum discord from the
qubits to the cavities and reservoirs. We show that this transfer occurs also
when the cavities are not entangled. Moreover, we discuss how quantum discord
can be extracted from the cavities and transferred to distant systems by
traveling leaking photons, using the input-output theory.Comment: 12 pages, 3 figures, to be published in International Journal of
Quantum Informatio
- …