Jun-Tao Chang

Dynamical evolution of correlated spontaneous emission of a single photon from a uniformly excited cloud of N atoms.

We study the correlated spontaneous emission from a dense spherical cloud of N atoms uniformly excited by absorption of a single photon. We find that the decay of such a state depends on the relation between an effective Rabi frequency Omega proportional square root N and the time of photon flight through the cloud R/c. If OmegaR/c<1 the state exponentially decays with rate Omega(2)R/c and the state lifetime is greater than R/c. In the opposite limit OmegaR/c>>1, the coupled atom-radiation system oscillates between the collective Dicke state (with no photons) and the atomic ground state (with one photon) with frequency Omega while decaying at a rate c/R.

Cooperative spontaneous emission as a many-body eigenvalue problem

We study emission of a single photon from a spherically symmetric cloud of

XUV coherent Raman superradiance

N

Atom microscopy beyond diffraction limit by resonance fluorescence spectroscopy

atoms (one atom is excited;

Cooperative spontaneous emission of N atoms: Many-body eigenstates, the effect of virtual Lamb shift processes, and analogy with radiation of N classical oscillators

N\ensuremath{-}1

Comment on: “Effects of including the counterrotating term and virtual photons on the eigenfunctions and eigenvalues of a scalar photon collective emission theory” [Phys. Lett. A 372 (2008) 2514]

are in the ground state) and present an exact analytical expression for eigenvalues and eigenstates of this many-body problem. We found that some states decay much faster than the single-atom decay rate, while other states are trapped and undergo very slow decay. When the size of the atomic cloud is small compared with the radiation wavelength, we found that the radiation frequency undergoes a large shift.

Distilling two-atom distance information from intensity-intensity correlation functions

We find that intense short pulses of XUV radiation can be produced by cooperative spontaneous emission from visible or IR laser pulses driving atoms or ions. The process depends on the generation and utilization of atomic coherence as is the case in lasing without inversion. However, the radiation process is not stimulated emission, but is rather cooperative spontaneous emission in the sense of Dicke. More precisely, the many atom mathematics of superradiance has much in common with coherent anti-Stokes Raman scattering. †It is a pleasure to dedicate this article to Professor Lorenzo Narducci: scientist, scholar, savant. All who were touched by him were enriched. The generation of Raman coherence is considered from the perspectives of multi-photon excitation and breaking of adiabaticity. In particular, we find that the advent of an ultrashort (e.g. single cycle) pulse rewards rethinking of conventional (nanosecond) nonlinear optics with new insights.

Three-qubit phase gate based on cavity quantum electrodynamics

We proposed an atom microcopy scheme measuring distance between two identical atoms placed in a standing wave laser field by measuring fluorescence spectrum or g2 functionpsilas spectrum. It has fractional-wavelength precision from about lambda/550 to lambda/2 .