Related papers: Lasing without inversion in a closed four-level sy…
We study a two-level system (atom, superconducting qubit or quantum dot) strongly coupled to the single photonic mode of a cavity, in the presence of incoherent pumping and including detuning and dephasing. This system displays a striking…
Bare-state population inversion is demonstrated in a two-level system with all dipole matrix elements nonzero. A laser field is resonantly driving the sample whereas a second weaker and lower frequency coherent field additionally pumps it…
We investigate the relationship between stability, adiabaticity and transfer efficiency in a \Lambda-type atom-molecule coupling system via a nonlinear stimulated Raman adiabatic passage. We find that only when the pump and control lasers…
We have observed clear Rabi oscillations of a weak probe in a strongly driven three-level lambda system in laser-cooled rubidium for the first time. When the coupling field is non-adiabatically switched on using a Pockels cell, transient…
We present a theoretical investigation of a three-level $\Lambda$-type atom driven by a strong coherent laser and a weak stochastic field exhibiting amplitude and phase fluctuations. The stochastic field is modeled as a complex…
We obtain gain of the probe field at multiple frequencies in a closed three-level V-type system using frequency modulated pump field. There is no associated population inversion among the atomic states of the probe transition. We describe…
The interaction of laser cooled and trapped atoms with resonant light is limited by the linewidth of the excited state of the atom. Another precise optical oscillator is an optical Fabry-P\'erot cavity. The combining of cold atoms with…
We investigate laser-induced quantum interference phenomena in superradiance processes and in an ensemble of initially excited $\Lambda-$type closely packed three-level emitters. The lower doublet levels are pumped with a coherent laser…
We discuss radiative corrections to an atomic two-level system subject to an intense driving laser field. It is shown that the Lamb shift of the laser-dressed states, which are the natural state basis of the combined atom-laser system,…
We predict collective 'free-space' lasing in a dense nanoscopic emitter arrangement where dipole-dipole coupled atomic emitters synchronize their emission and exhibit lasing behavior without the need for an optical resonator. At the example…
We propose a scheme for creating atomic coherent superpositions via stimulated Raman adiabatic passage in a Lambda-type system where the final state has twofold levels. In the employ of a control field, the presence of double dark states…
Amplitude and phase control of gain without inversion is investigated in a four level loop-structure atomic system. Two features are presented. One is that gain without inversion can be obtained through the amplitude control of the applied…
We consider a system composed of a single artificial atom coupled to a cavity mode. The artificial atom is biased such that the most dominant relaxation process in the system takes the atom from its ground state to its excited state, thus…
Highly stable laser sources based on narrow atomic transitions provide a promising platform for direct generation of stable and accurate optical frequencies. Here we investigate a simple system operating in the high-temperature regime of…
We show theoretically that by applying a bichromatic electromagnetic field, the dressed states of a monochromatically driven two-level atom can be pumped into a coherent superposition termed as dressed-state coherent population trapping.…
We investigate spontaneous radiative processes in a driven polar two-level system whose interaction with the laser field is dominated by broken inversion symmetry rather than by the usual transition dipole coupling. Using a polaron…
We propose that in the presence of an Ohmic, de-phasing type environment, a two-level-cavity system undergoes a quantum phase transition from a state with damped Rabi oscillation to a state without. We present the phase diagram and make…
We show that it is possible to realize simultaneous Raman lasing at two different frequencies using a double-$\Lambda$ system pumped by a bi-frequency field. The Raman lasers are phase-locked to one another, and the beat-frequency matches…
We study a system of two quantum dots, each with several discrete levels, which are coherently coupled to a microwave oscillator. They are attached to electronic leads and coupled to a phonon bath, both leading to inelastic processes. For a…
We investigate the transient response of a $\Lambda$-type system with one transition decaying to a modified radiation reservoir with an inverse square-root singular density of modes at threshold, under conditions of transparency. We…