title: Photon recoil momentum in dispersive media.
abstract: A systematic shift of the photon recoil momentum due to the index of refraction of a dilute gas of atoms has been observed. The recoil frequency was determined with a two-pulse light grating interferometer using near-resonant laser light. The results show that the recoil momentum of atoms caused by the absorption of a photon is n variant Planck's k, where n is the index of refraction of the gas and k is the vacuum wave vector of the photon. This systematic effect must be accounted for in high-precision atom interferometry with light gratings.
authors.affiliation: MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Gretchen K
authors.initials: GK
authors.lastname: Campbell
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Leanhardt
authors.forename: Jongchul
authors.initials: J
authors.lastname: Mun
authors.forename: Micah
authors.initials: M
authors.lastname: Boyd
authors.forename: Erik W
authors.initials: EW
authors.lastname: Streed
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ketterle
authors.forename: David E
authors.initials: DE
authors.lastname: Pritchard