Controlling statistical properties of a Cooper pair box interacting with a nanomechanical resonator

Abstract

We consider the Jaynes-Cummings model describing the interaction of a Cooper pair box (CPB ) and a nanoresonator (NR) in the presence of a Kerr medium and losses The evolution of the entropy of both subsystems and the CPB population inversion were calculated numerically. It is found that these properties increase when the NR frequency is time-dependent, even in the presence of losses; the effect is very sensitive to detuning and disappears in the resonant regime. The roles played by the losses affecting the CPB and the NR are also compared.

Controlling the non-classical properties of a hybrid Cooper pair box system and an intensity dependent nanomechanical resonator

“…We consider = 1 and assume as identical the four Josephson junctions of the circuit system, having the same Josephson energy E 0 J ; the external fluxes Φ L and Φ r are also assumed as identical in magnitude, although they have opposite signs Φ L = −Φ r = Φ x (see Ref. [8]). So, taking into account the decay in the excited level of the CPB and dissipation in the NR, we can write the total Hamiltonian of the system as follows,…”

Using a hybrid system (Cooper pair box plus nanomechanical resonator) in the presence of Kerr nonlinearities and losses to control the entropy of the subsystems

“…and χ(t) = χ 0 +εf (t) [23,24]. In addition we consider the presence of the term κ(t) standing for the time-dependent loss affecting the CPB, the term δ(t) being the same for the NR, and χ(t) is the response time of the Kerr medium.…”

Entanglement Dynamics Induced by a Squeezed Coherent Cavity Coupled Nonlinearly with a Qubit and Filled with a Kerr-Like Medium

“…The qubit-field interactions are generalized to intensity-dependent qubit-field coupling [ 32 ]. The effects of the intensity-dependent coupling on the non-classical effects have been studied in a hybrid Cooper pair box qubit interacting with a resonator [ 33 , 34 ]. It is used to enhance the non-local correlations of two coupled qubits [ 35 ].…”