In a previous work [Commun. Theor. Phys. 45 （2006） 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Ja...In a previous work [Commun. Theor. Phys. 45 （2006） 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Jaynes-Cummings model in the effective Hamiltonian approach. This comment presents an alternative method, based on the so called ＂full two-photon Jaynes-Cummings Hamiltonian approach＂. Accordingly, it describes the evolution of the two-photon degenerate process for arbitrary average photon number inside the cavity, as the correct way to implement teleportation in this scenario.展开更多
We propose a scheme to transmit information via the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success prob...We propose a scheme to transmit information via the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success probability and the fidelity are calculated and compared with those obtained in an atom-field system in different regimes. Addtionaly, the scheme can also be applied to prepare low excited Fock states.展开更多
We present a scheme using four two-level atoms and a bimodal cavity to get approximate conditional teleportation of an arbitrary entangled atomic state without using the Bell-state measurement.
Inspired by a recent paper [2002 J. Opt. B 4 316] we present an alternative scheme to teleport an entanglement of zero- and one-photon states of a running-wave field. The scheme employs only linear optical elements pl...Inspired by a recent paper [2002 J. Opt. B 4 316] we present an alternative scheme to teleport an entanglement of zero- and one-photon states of a running-wave field. The scheme employs only linear optical elements plus single-photon sources and detectors.展开更多
We investigate the action of time-dependent detunings upon the excitation inversion of a Cooper pair box interacting with a nanomechanical resonator.The method employs the Jaynes–Cummings model with damping,assuming ...We investigate the action of time-dependent detunings upon the excitation inversion of a Cooper pair box interacting with a nanomechanical resonator.The method employs the Jaynes–Cummings model with damping,assuming different decay rates of the Cooper pair box and various fixed and time-dependent detunings.It is shown that,when the presence of damping plus constant detunings destroys the collapse/revival effects,convenient choices of time-dependent detunings allow one to reconstruct such events in a perfect way.It is also shown that the mean excitation of the nanomechanical resonator is more robust against damping of the Cooper pair box for convenient values of time-dependent detunings.展开更多
In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the c...In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the controlled creation of an arbitrary number of holes.展开更多
文摘In a previous work [Commun. Theor. Phys. 45 （2006） 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Jaynes-Cummings model in the effective Hamiltonian approach. This comment presents an alternative method, based on the so called ＂full two-photon Jaynes-Cummings Hamiltonian approach＂. Accordingly, it describes the evolution of the two-photon degenerate process for arbitrary average photon number inside the cavity, as the correct way to implement teleportation in this scenario.
基金Project supported by the FAPEG (CV)INCT-IQ (ATA)the CNPq (ATA,BB)
文摘We propose a scheme to transmit information via the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success probability and the fidelity are calculated and compared with those obtained in an atom-field system in different regimes. Addtionaly, the scheme can also be applied to prepare low excited Fock states.
文摘We present a scheme using four two-level atoms and a bimodal cavity to get approximate conditional teleportation of an arbitrary entangled atomic state without using the Bell-state measurement.
文摘Inspired by a recent paper [2002 J. Opt. B 4 316] we present an alternative scheme to teleport an entanglement of zero- and one-photon states of a running-wave field. The scheme employs only linear optical elements plus single-photon sources and detectors.
基金Supported by the FAPEG(CV)and CNPq(ATA,BB),Brasilian Agencies.
文摘We investigate the action of time-dependent detunings upon the excitation inversion of a Cooper pair box interacting with a nanomechanical resonator.The method employs the Jaynes–Cummings model with damping,assuming different decay rates of the Cooper pair box and various fixed and time-dependent detunings.It is shown that,when the presence of damping plus constant detunings destroys the collapse/revival effects,convenient choices of time-dependent detunings allow one to reconstruct such events in a perfect way.It is also shown that the mean excitation of the nanomechanical resonator is more robust against damping of the Cooper pair box for convenient values of time-dependent detunings.
基金Supported in part by CAPES,CNPq and MCT/PRONEX,Brazilian agencies。
文摘In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the controlled creation of an arbitrary number of holes.
