Atomic coherence

About: Atomic coherence is a research topic. Over the lifetime, 877 publications have been published within this topic receiving 29395 citations.

Observation of two electromagnetically induced absorption in one system using two coupling fields

Abstract: We have experimentally investigated electromagnetically induced absorption (EIA) resonance in an atomic cesium system with two strongly coupled laser fields and one probe laser field. We observed the transformation of V-type electromagnetically induced transparency (EIT) in a three-level system to asymmetric N-scheme EIA with two EIA peaks. The width and the relative magnitude of the EIA were modified by changing the intensity of one of the coupling laser fields. The eects may be useful for real applications.

Intensity dependence suppression and enhancement of four-wave mixing in a micrometric thin vapour

Abstract: We theoretically investigate dressed-four-wave mixing (dressed-FWM) spectroscopy of rubidium atoms in a micrometric thin vapour. It is found that Dike-narrowing type Autler–Townes (AT) spectroscopy with high resolution can be achieved in a reverse Y-type four-level atomic system due to the phase-conjugated configuration of laser beams and the transient effects of atom–wall collision in the thin vapour. We also show that controllable suppression and enhancement of the dressed-FWM signal due to the evolution of atomic coherence can be obtained by selecting different coupling field intensities at the proper detuning of the probe and the coupling fields. This control of FWM processes can be interpreted by dressed state analysis and probably used in the design of optical switch and the enhancement of FWM processes for frequency conversion.

Nonlinear magneto-optic effect based on atomic coherence in Rb D 1 -line

Abstract: We have observed the nonlinear magneto-optic effect(NMOE) based on atomic coherence in Rb D-line using the Rb vapor cell containing 50 Torr of Ne. The width of the NMOE signal was measured to be 2464 Hz, when the peak-to-peak B-field variation was 1 mGauss. The result of this work may be applied to a high-sensitivity magnetometer.

Strong-field index enhancement via incoherent excitation

Abstract: We show that it is possible, in principle, to employ an incoherent field as a control field to achieve maximal atomic coherence for a probe field, which characterizes ultralarge index of refraction and vanishing absorption. For this purpose we consider a three-level V system in which there are two dipole transitions, of which one is weak and the other is strong. The strong probe field is applied to the weak transition and the incoherent field drives the strong transition. For such an arrangement, selective dressed-population trapping, which corresponds to maximal atomic coherence, is established by relying on the incoherent field and the spontaneous relaxation to transfer population from one dressed state to the other. This scheme as an extreme example explains that strong-field index enhancement based on selective dressed-population trapping is resistant to the control field fluctuations.

Entanglement dynamics of two atoms successively passing a cavity

Abstract: By means of concurrence, we investigate the dynamics of entanglement between two initially separate atoms in succession passing through a cavity and their interaction with a Fock state field. We then analyze the effects of the atomic coherence, photon number, and atomic motion on the time evolution of atom-atom entanglement. The results show that there can be entanglement between two separate atoms, and that the threshold time for the creation of the entanglement is controllable by the photon number, atomic motion, and field-mode structure.