Subwavelength atom localization via amplitude and phase control of the absorption spectrum
Abstract
We propose a scheme for subwavelength localization of an atom conditioned upon the absorption of a weak probe field at a particular frequency. Manipulating atom-field interaction on a certain transition by applying drive fields on nearby coupled transitions leads to interesting effects in the absorption spectrum of the weak probe field. We exploit this fact and employ a four-level system with three driving fields and a weak probe field, where one of the drive fields is a standing-wave field of a cavity. We show that the position of an atom along this standing wave is determined when probe-field absorption is measured. We find that absorption of the weak probe field at a certain frequency leads to subwavelength localization of the atom in either of the two half-wavelength regions of the cavity field by appropriate choice of the system parameters. We term this result as sub-half-wavelength localization to contrast it with the usual atom localization result of four peaks spread over one wavelength of the standing wave. We observe two localization peaks in either of the two half-wavelength regions along the cavity axis.
Description
Journals published by the American Physical Society can be found at http://publish.aps.org/Subject
ELECTROMAGNETICALLY INDUCED TRANSPARENCYAUTLER-TOWNES MICROSCOPY
POSITION MEASUREMENT
SPONTANEOUS EMISSION
OPTICAL-FIELDS
QUANTUM
INTERFERENCE
SINGLE-ATOM
DIFFRACTION
INTERFEROMETRY
SPECTROSCOPY
Optics
Physics