We theoretically investigate the generation of steady-state entanglement in a levitated optomechanical system with a cascade three-level atomic medium and a dielectric nanosphere. There are two cavity modes, driven by two external laser beams with different frequencies, which are responsible for trapping and cooling the nanosphere. Atoms prepared in coherent superposition are injected into the cavity to manipulate the optical fields and the effective optomechanical coupling. We show that the entanglement between the nanosphere and the cavity modes can be enhanced by selecting properly the initial population of the lower atomic level. In particular, when the atoms are prepared at that level, the corresponding optomechanical entanglement increases with the increase of the atom-field coupling strength. We also investigate in detail the influence of the effective cavity field detunings, the atomic detunings, the driving power, and the nanosphere's radius and found that there exist optimal values of the effective cavity field detuning and the driving power that maximize the optomechanical entanglement. By selecting the system's parameters properly, we further demonstrate the generation of genuine tripartite entanglement between three degrees of freedom in the system. The findings here may help flexible control of the steady-state entanglement in hybrid optomechanical systems.We theoretically investigate the generation of steady-state entanglement in a levitated optomechanical system with a cascade three-level atomic medium and a dielectric nanosphere. There are two cavity modes, driven by two external laser beams with different frequencies, which are responsible for trapping and cooling the nanosphere. Atoms prepared in coherent superposition are injected into the cavity to manipulate the optical fields and the effective optomechanical coupling. We show that the entanglement between the nanosphere and the cavity modes can be enhanced by selecting properly the initial population of the lower atomic level. In particular, when the atoms are prepared at that level, the corresponding optomechanical entanglement increases with the increase of the atom-field coupling strength. We also investigate in detail the influence of the effective cavity field detunings, the atomic detunings, the driving power, and the nanosphere's radius and found that there exist optimal values of the effective cavity field detuning and the driving power that maximize the optomechanical entanglement. By selecting the system's parameters properly, we further demonstrate the generation of genuine tripartite entanglement between three degrees of freedom in the system. The findings here may help flexible control of the steady-state entanglement in hybrid optomechanical systems.

Physical Review ADec 1, 202012 citations

Entanglement created by spontaneously generated coherence

Zhao-Hong Tang, Gao‐xiang Li, Z. Ficek

We propose a scheme that is able to generate on demand a steady-state entanglement between two nondegenerate cavity modes. The scheme relies on the interaction of the cavity modes with driven two- or three-level atoms, which act as a coupler to build entanglement between the modes. We show that, in the limit of a strong driving, it is crucial for the generation of entanglement between the modes to imbalance populations of the dressed states of the driven atomic transition. In the case of a three-level $V$ -type atom, we find that a stationary entanglement can be created on demand by tuning the Rabi frequency of the driving field to the difference between the atomic transition frequencies. The resulting degeneracy of the energy levels, together with the spontaneously generated coherence, generate a steady-state entanglement between the cavity modes. It is shown that the condition for the maximal entanglement coincides with the collapse of the atomic system into a pure trapping state. We also show that the creation of entanglement depends strongly on the mutual polarization of the transition atomic dipole moments.We propose a scheme that is able to generate on demand a steady-state entanglement between two nondegenerate cavity modes. The scheme relies on the interaction of the cavity modes with driven two- or three-level atoms, which act as a coupler to build entanglement between the modes. We show that, in the limit of a strong driving, it is crucial for the generation of entanglement between the modes to imbalance populations of the dressed states of the driven atomic transition. In the case of a three-level $V$-type atom, we find that a stationary entanglement can be created on demand by tuning the Rabi frequency of the driving field to the difference between the atomic transition frequencies. The resulting degeneracy of the energy levels, together with the spontaneously generated coherence, generate a steady-state entanglement between the cavity modes. It is shown that the condition for the maximal entanglement coincides with the collapse of the atomic system into a pure trapping state. We also show that the creation of entanglement depends strongly on the mutual polarization of the transition atomic dipole moments.

arXiv:1010.1067Physical Review ADec 29, 201026 citations

Dynamical entanglement of three-level atoms

Lech Jakóbczyk

Oct 1, 20100 citations

Entanglement of two coupled two-level atoms

Suttipong Locharoenrat

Sep 3, 20140 citations

The Effect of Parametric Amplifier on Entanglement and Statistical Properties of Nondegenerate Three-Level Laser Pumped by Electron Bombardment

Tamirat Abebe

In this paper, the quantum properties of an electrically pumped non-degenerate three level laser with two mode subharmonic generator coupled to a two-mode vacuum reservoirs via a single-port mirror whose open cavity contains N non-degenerate three-level cascade atoms is presented. The analysis is carried out by putting the noise operators associated with a vacuum reservoir in normal order. It is found that the photons as well as atoms of the system are strongly entangled at steady state. It has been shown that the degree of photon entanglement greater than that of atom entanglement. Moreover, the presence of the subharmonic generator leads to an increase in the degree of entanglement.In this paper, the quantum properties of an electrically pumped non-degenerate three level laser with two mode subharmonic generator coupled to a two-mode vacuum reservoirs via a single-port mirror whose open cavity contains N non-degenerate three-level cascade atoms is presented. The analysis is carried out by putting the noise operators associated with a vacuum reservoir in normal order. It is found that the photons as well as atoms of the system are strongly entangled at steady state. It has been shown that the degree of photon entanglement greater than that of atom entanglement. Moreover, the presence of the subharmonic generator leads to an increase in the degree of entanglement.

Global Journal of Human Social ScienceOct 1, 20180 citations

V

-type atom, we find that a stationary entanglement can be created on demand by tuning the Rabi frequency of the driving field to the difference between the atomic transition frequencies. The resulting degeneracy of the energy levels, together with the spontaneously generated coherence, generate a steady-state entanglement between the cavity modes. It is shown that the condition for the maximal entanglement coincides with the collapse of the atomic system into a pure trapping state. We also show that the creation of entanglement depends strongly on the mutual polarization of the transition atomic dipole moments.