We show that an absolute coherent phase of a laser can be used to manipulate the entanglement of photon pairs of two-photon laser. Our focus is on the generation of a continuous source of entangled photon pairs in the double $Λ$ (or Raman) scheme. We study the dependence of steady state entanglement on the phase and laser parameters. We obtain a relationship between entanglement and two-photon correlation. We derive conditions that give steady state entanglement for the Raman-EIT scheme and use it to identify region of steady state macroscopic entanglement. No entanglement is found for the double resonant Raman scheme for any laser parameters.We show that an absolute coherent phase of a laser can be used to manipulate the entanglement of photon pairs of two-photon laser. Our focus is on the generation of a continuous source of entangled photon pairs in the double $Λ$ (or Raman) scheme. We study the dependence of steady state entanglement on the phase and laser parameters. We obtain a relationship between entanglement and two-photon correlation. We derive conditions that give steady state entanglement for the Raman-EIT scheme and use it to identify region of steady state macroscopic entanglement. No entanglement is found for the double resonant Raman scheme for any laser parameters.

arXiv:quant-ph/0703084Mar 10, 20070 citations

Continuous source of phase-controlled entangled two-photon laser

C. H. Raymond Ooi

We show that an absolute coherent phase of a laser can be used to manipulate the entanglement of photon pairs in two-photon laser. We present simple physics behind a general master equation for two-photon laser. Our focus is on the generation of a continuous source of macroscopically entangled photon pairs in the double $\ensuremath{\Lambda}$ (or Raman) scheme. We show how the steady-state photon numbers and entanglement depend on the laser parameters, especially the phase. We obtain a relationship between entanglement and two-photon correlation. We derive conditions that give steady-state entanglement for the spontaneous Raman-electromagnetic-induced transparency scheme and use it to identify the region with macroscopic entanglement. No entanglement is found for the double resonant Raman scheme.We show that an absolute coherent phase of a laser can be used to manipulate the entanglement of photon pairs in two-photon laser. We present simple physics behind a general master equation for two-photon laser. Our focus is on the generation of a continuous source of macroscopically entangled photon pairs in the double $\ensuremath{\Lambda}$ (or Raman) scheme. We show how the steady-state photon numbers and entanglement depend on the laser parameters, especially the phase. We obtain a relationship between entanglement and two-photon correlation. We derive conditions that give steady-state entanglement for the spontaneous Raman-electromagnetic-induced transparency scheme and use it to identify the region with macroscopic entanglement. No entanglement is found for the double resonant Raman scheme.

Physical Review AJul 11, 200727 citations

Entanglement in quantum optics

P. Tombesi

Jan 1, 20060 citations

The optical quantum entanglement experiments

F. J. Duarte

Institute of Physics eBooksSep 1, 20220 citations

Entangled radiation via a Raman-driven quantum-beat laser

Sajid Qamar, M. Al-Amri, Shahid Qamar +1 more

We propose a scheme for the entanglement generation of two cavity modes using a four-level Raman-driven quantum-beat laser (QBL). The atomic coherence is generated by a Raman-type two-photon process. Two different sufficient conditions for entanglement generation have been investigated. The effect of cavity losses and strength of the driving fields on entanglement generation is studied for different initial states of the resonant cavity modes. The results are in agreement with the earlier scheme for the entanglement generation using a directly driven quantum-beat laser. We observe entanglement generation even for high cavity losses and with low strength of the driving fields. Further, there is no dipole-forbidden transition in the Raman-driven QBL system. Thus the proposed scheme for the entanglement generation is experimentally more viable as compared to the previous directly driven QBL system.We propose a scheme for the entanglement generation of two cavity modes using a four-level Raman-driven quantum-beat laser (QBL). The atomic coherence is generated by a Raman-type two-photon process. Two different sufficient conditions for entanglement generation have been investigated. The effect of cavity losses and strength of the driving fields on entanglement generation is studied for different initial states of the resonant cavity modes. The results are in agreement with the earlier scheme for the entanglement generation using a directly driven quantum-beat laser. We observe entanglement generation even for high cavity losses and with low strength of the driving fields. Further, there is no dipole-forbidden transition in the Raman-driven QBL system. Thus the proposed scheme for the entanglement generation is experimentally more viable as compared to the previous directly driven QBL system.

Physical Review ASep 10, 200930 citations

Λ

(or Raman) scheme. We study the dependence of steady state entanglement on the phase and laser parameters. We obtain a relationship between entanglement and two-photon correlation. We derive conditions that give steady state entanglement for the Raman-EIT scheme and use it to identify region of steady state macroscopic entanglement. No entanglement is found for the double resonant Raman scheme for any laser parameters.