arXiv subjects

M. M. Cola

Publications and source records attributed to M. M. Cola.

3 recordsLinked to original sources

arXiv2009

Recoil-induced subradiance in a cold atomic gas

Subradiance, i.e. the cooperative inhibition of spontaneous emission by destructive interatomic interference, can be realized in a cold atomic sample confined in a ring cavity and lightened by a two-frequency laser. The atoms, scattering the photons of the two laser fields into the cavity-mode, recoil and change their momentum. Under proper conditions the atomic initial momentum state and the first two momentum recoil states form a three-level degenerate cascade. A stationary subradiant state is obtained after that the scattered photons have left the cavity, leaving the atoms in a coherent superposition of the three collective momentum states. After a semiclassical description of the process, we calculate the quantum subradiant state and its Wigner function. Anti-bunching and quantum correlations between the three atomic modes of the subradiant state are demonstrated.

cond-mat.other↗

arXiv2006

Parametric optimization for an x-ray Free Electron Laser with a laser wiggler

In this paper we optimize the experimental parameters to operate a Free Electron Laser with a laser wiggler in the Angstrom region. We show that the quantum regime of the Self Amplified Spontaneous Emission (Quantum SASE) may be reached with realistic parameters. The classical SASE regime is also discussed and compared with the quantum regime.

physics.acc-ph↗

arXiv2004

A quantum model for collective recoil lasing

Free Electron Laser (FEL) and Collective Atomic Recoil Laser (CARL) are described by the same model of classical equations for properly defined scaled variables. These equations are extended to the quantum domain describing the particle's motion by a Schrödinger equation coupled to a self-consistent radiation field. The model depends on a single collective parameter $\bar ρ$ which represents the maximum number of photons emitted per particle. We demonstrate that the classical model is recovered in the limit $\bar ρ\gg 1$, in which the Wigner function associated to the Schrödinger equation obeys to the classical Vlasov equation. On the contrary, for $\bar ρ\le 1$, a new quantum regime is obtained in which both FELs and CARLs behave as a two-state system coupled to the self-consistent radiation field and described by Maxwell-Bloch equations.

quant-ph↗