title: Optical response of gas-phase atoms at less than λ/80 from a dielectric surface.
abstract: We present experimental observations of atom-light interactions within tens of nanometers (down to 11 nm) of a sapphire surface. Using photon counting we detect the fluorescence from of order one thousand Rb or Cs atoms, confined in a vapor with thickness much less than the optical excitation wavelength. The asymmetry in the spectral line shape provides a direct readout of the atom-surface potential. A numerical fit indicates a power law -C(α)/r(α) with α = 3.02 ± 0.06 confirming that the van der Waals interaction dominates over other effects. The extreme sensitivity of our photon-counting technique may allow the search for atom-surface bound states.
authors.affiliation: Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: K A
authors.initials: KA
authors.lastname: Whittaker
authors.affiliation: Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Keaveney
authors.affiliation: Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: I G
authors.initials: IG
authors.lastname: Hughes
authors.affiliation: Institute for Physical Research, National Academy of Sciences, Ashtarak 2, 0203, Armenia.
authors.forename: A
authors.initials: A
authors.lastname: Sargsyan
authors.affiliation: Institute for Physical Research, National Academy of Sciences, Ashtarak 2, 0203, Armenia.
authors.forename: D
authors.initials: D
authors.lastname: Sarkisyan
authors.affiliation: Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: C S
authors.initials: CS
authors.lastname: Adams