Synopsis: Supercontrol of superradiance

Precise control of coherent states of both light and matter is achieved by placing a Bose-Einstein condensate in a narrow-band optical cavity.
Synopsis figure
H. Kessler et al., Phys. Rev. Lett. (2014)

Since the 1950s, physicists have studied “superradiance,” a form of enhanced emission of radiation occurring when a collection of atoms can emit light as if they were one single quantum mechanical system. The main requirement to achieve superradiance is that the wavelength of the light be much larger than the average separation of the atoms, so that they can interact coherently.

More recently, ultracold atom technology has allowed researchers to explore the interaction of photons with coherent ensembles of atoms (matter waves). This can lead to a regime called matter-wave superradiance, in which superradiant scattering of light is coupled to a coherent, directional beam of recoiling atoms with a very well defined momentum distribution.

In a paper in Physical Review Letters, researchers in the laboratory of Andreas Hemmerich at the University of Hamburg, Germany, report experiments in which matter-wave superradiance can be precisely controlled by placing a cigar-shaped Bose-Einstein condensate inside a resonant optical cavity with a very narrow resonant linewidth. A monochromatic laser, slightly detuned from the cavity resonance, experiences Rayleigh scattering from the coherent blob of atoms.

As the authors demonstrate with imaging studies, under certain resonant conditions a regime can be reached in which standing matter and optical waves are strongly coupled. In such a regime, the recoiling atoms remain coherent but are shifted into a new state of higher momentum and emit coherent, superradiant light pulses. Because the optical cavity is narrow band, only a restricted and precisely defined set of motional states couples to the light. This could be used to speed up, slow down, or redirect coherent collections of atoms for high-precision metrology purposes. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Atomic and Molecular Physics

Previous Synopsis

Next Synopsis

Atomic and Molecular Physics

Knots for All Occasions

Read More »

Related Articles

Synopsis: Atoms Feel New Force
Atomic and Molecular Physics

Synopsis: Atoms Feel New Force

Laser light can stretch and squeeze a whole cloud of atoms with a collective force. Read More »

Synopsis: Direct View of Exchange Symmetry
Quantum Physics

Synopsis: Direct View of Exchange Symmetry

A proposed set of experiments could offer a direct measurement of the fundamental quantum property that distinguishes fermions from bosons. Read More »

Synopsis: Topological Defect on the Move
Condensed Matter Physics

Synopsis: Topological Defect on the Move

Researchers have directed the motion of a domain-wall-like topological defect through a crystal of trapped ions. Read More »

More Articles