Tunneling Control of Optical Properties of a Quantum Well from Adjacent Quantum Well by Coherent Population Trapping Effect

The coherent population trapping effect in double tunnel-coupled quantum wells is analyzed. One of two quantum wells interacts with the two-frequency laser radiation and low-frequency field, thus forming a closed contour of excitation. It is possible to control the excited level population in such a scheme of excitation by changing relative phases of the fields in the coherent population trapping state. The quantum well is bound to the other quantum well by tunnel coupling of the excited levels, therefore the population and optical properties of the other quantum well depend on the coherent population trapping state in the first quantum well and can be controlled

Generalized Hyper-Ramsey spectroscopy in an optically dense medium

International audienceThe peculiarities of Ramsey resonance and its sensitivity to the light shift from an optically dense medium of cold atoms are investigated. Different composite pulse protocols for clock spectroscopy, including hyper-Ramsey, modified and generalised hyper-Ramsey schemes, are compared. Error signals change significantly due to the processes of absorption and dispersion in the atomic medium. The dependence of the position of the central fringe resonance with a residual uncompensated light shift of the atomic transition is studied with the attenuation of the radiation intensity in the medium taken into account. It is shown that using a combination of generalised hyper-Ramsey error signals allows one to suppress the sensitivity to the light shift for any length of the medium

Tunneling Control of Optical Properties of a Quantum Well from Adjacent Quantum Well by Coherent Population Trapping Effect

The coherent population trapping effect in double tunnel-coupled quantum wells is analyzed. One of two quantum wells interacts with the two-frequency laser radiation and low-frequency field, thus forming a closed contour of excitation. It is possible to control the excited level population in such a scheme of excitation by changing relative phases of the fields in the coherent population trapping state. The quantum well is bound to the other quantum well by tunnel coupling of the excited levels, therefore the population and optical properties of the other quantum well depend on the coherent population trapping state in the first quantum well and can be controlled

Generalised hyper-Ramsey spectroscopy of two-level atoms in an optically dense medium

International audienceThe peculiarities of Ramsey resonance and its sensitivity to the light shift from an optically dense medium of cold atoms are investigated. Different composite pulse protocols for clock spectroscopy, including hyper-Ramsey, modified and generalised hyper-Ramsey schemes, are compared. Error signals change significantly due to the processes of absorption and dispersion in the atomic medium. The dependence of the position of the central fringe resonance with a residual uncompensated light shift of the atomic transition is studied with the attenuation of the radiation intensity in the medium taken into account. It is shown that using a combination of generalised hyper-Ramsey error signals allows one to suppress the sensitivity to the light shift for any length of the medium