title: Combining red and blue-detuned optical potentials to form a Lamb-Dicke trap for a single neutral atom.
abstract: We propose and demonstrate a scheme for strong radial confinement of a single 87 Rb atom by a bichromatic far-off resonance optical dipole trap (BFORT). The BFORT is composed of a blue-detuned Laguerre-Gaussian LG01 beam and a red-detuned Gaussian beam. The atomic oscillation frequency measurement shows that the effective trapping dimension is much sharper than that from a diffraction-limited microscopic objective. Theory shows that the added scattering rate due to imposing blue-detuned light is negligible when the temperature of the single atoms is close to ground state temperature. By carrying out sub-Doppler cooling, the mean energy of single atoms trapped in the BFORT is reduced to 15 ± 1 μK. The corresponding mean quantum number of radial vibration n is about 1.65, which satisfies the Lamb-Dicke regime. We conclude that the BFORT is a suitable Lamb-Dicke trap for further cooling a single neutral atom down to the ground state and for further application in quantum information processing.
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences - Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: He
authors.forename: Shi
authors.initials: S
authors.lastname: Yu
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Zhan