We report an experimental study of one- and two-photon Rabi oscillations and other coherent effects in microwave transitions between Rydberg states of calcium. Selective field ionization allows us to observe the time evolution of both the initial and final states with high discrimination. The experiments include measurements of the dependence of the one- and two-photon oscillation frequencies on microwave power and detuning from resonance. We have used the off-resonant behavior of the two-photon oscillation frequency to measure the ac Stark shift. In a magnetic field we have also observed the free evolution of the magnetic sublevels and the effect of Zeeman splitting on the one-photon Rabi oscillations. The theory for these experiments is presented; our results are in excellent agreement.We report an experimental study of one- and two-photon Rabi oscillations and other coherent effects in microwave transitions between Rydberg states of calcium. Selective field ionization allows us to observe the time evolution of both the initial and final states with high discrimination. The experiments include measurements of the dependence of the one- and two-photon oscillation frequencies on microwave power and detuning from resonance. We have used the off-resonant behavior of the two-photon oscillation frequency to measure the ac Stark shift. In a magnetic field we have also observed the free evolution of the magnetic sublevels and the effect of Zeeman splitting on the one-photon Rabi oscillations. The theory for these experiments is presented; our results are in excellent agreement.

Physical Review ANov 1, 1989125 citations

Two-photon Rabi oscillations in a single In x Ga 1 − x As ∕ Ga As quantum dot

Stefan Stufler, Paweł Machnikowski, Patrick Ester +4 more

We report on Rabi oscillations of the biexciton in a single ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dot, induced via a coherent two-photon process. In contrast to single-exciton Rabi oscillations the measured population oscillation is not purely sinusoidal in excitation pulse area. The experimental results are well reproduced by a theoretical calculation that relies only on the pulse shape and biexciton binding energy. Dephasing times of the biexciton are similar to those of the single exciton under the applied measurement conditions reaching up to $220\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$ .We report on Rabi oscillations of the biexciton in a single ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dot, induced via a coherent two-photon process. In contrast to single-exciton Rabi oscillations the measured population oscillation is not purely sinusoidal in excitation pulse area. The experimental results are well reproduced by a theoretical calculation that relies only on the pulse shape and biexciton binding energy. Dephasing times of the biexciton are similar to those of the single exciton under the applied measurement conditions reaching up to $220\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$.

Physical Review BMar 7, 2006206 citations

Spectral collapse in two-mode two-photon Rabi model

Chi‐Fai Lo

Physica A Statistical Mechanics and its ApplicationsMar 19, 20211 citation

Multiphoton quantum Rabi oscillations in ultrastrong cavity QED

Luigi Garziano, Roberto Stassi, Vincenzo Macrí +3 more

When an atom is strongly coupled to a cavity, the two systems can exchange a single photon through a coherent Rabi oscillation. This process enables precise quantum-state engineering and manipulation of atoms and photons in a cavity, which play a central role in quantum information and measurement. Recently, a new regime of cavity QED was reached experimentally where the strength of the interaction between light and artificial atoms (qubits) becomes comparable to the atomic transition frequency or the resonance frequency of the cavity mode. Here we show that this regime can strongly modify the concept of vacuum Rabi oscillations, enabling multiphoton exchanges between the qubit and the resonator. We find that experimental state-of-the-art circuit-QED systems can undergo two- and three-photon vacuum Rabi oscillations. These anomalous Rabi oscillations can be exploited for the realization of efficient Fock-state sources of light and complex entangled states of qubits.When an atom is strongly coupled to a cavity, the two systems can exchange a single photon through a coherent Rabi oscillation. This process enables precise quantum-state engineering and manipulation of atoms and photons in a cavity, which play a central role in quantum information and measurement. Recently, a new regime of cavity QED was reached experimentally where the strength of the interaction between light and artificial atoms (qubits) becomes comparable to the atomic transition frequency or the resonance frequency of the cavity mode. Here we show that this regime can strongly modify the concept of vacuum Rabi oscillations, enabling multiphoton exchanges between the qubit and the resonator. We find that experimental state-of-the-art circuit-QED systems can undergo two- and three-photon vacuum Rabi oscillations. These anomalous Rabi oscillations can be exploited for the realization of efficient Fock-state sources of light and complex entangled states of qubits.

arXiv:1509.06102Physical Review ADec 18, 2015155 citations

Dynamics of a two-photon laser

Daniel J. Gauthier, Olivier Pfister, William J. Brown +1 more

Springer eBooksJan 1, 20030 citations

220\phantom{\rule{0.3em}{0ex}}\mathrm{ps}