Quantum Effects in Optical Control of Atomic Motion

Sönke Schmidt

Leonid Förster, Michał Karski, Jai-Min Choi +8 more

We control the quantum mechanical motion of neutral atoms in an optical lattice by driving microwave transitions between spin states whose trapping potentials are spatially offset. Control of this offset with nanometer precision allows for adjustment of the coupling strength between different motional states, analogous to an adjustable effective Lamb-Dicke factor. This is used both for efficient one-dimensional sideband cooling of individual atoms to a vibrational ground state population of 97% and to drive coherent Rabi oscillation between arbitrary pairs of vibrational states. We further show that microwaves can drive well resolved transitions between motional states in maximally offset, shallow lattices, and thus in principle allow for coherent control of long-range quantum transport.

Dan Steck

C. H. Raymond Ooi

The Doppler effect of moving atoms can create irreversibility of light. We show that the laser field in an electromagnetic induced transparency (EIT) scheme with atomic motion can control the directional propagation of two counter-propagating output probe fields in an atomic gas. Quantum coherence and the Doppler effect enable the system to function like an optical transistor with two outputs that can generate states analogous to the Bell basis. Interference of the two output fields from the gas provides useful features for determining the mean atomic velocity and can be used as a sensitive quantum velocimeter. Some subtle physics of EIT is also discussed. In particular, the sign of the dispersive phase in EIT is found to have a unique property, which helps to explain certain features in the interference.

C. H. Raymond Ooi

The Doppler effect of moving atoms can create irreversibility of light. We show that the laser field in electromagnetic induced transparency (EIT) scheme with atomic motion can control the directional propagation of two counter-propagating probe fields in atomic gas cell. The quantum coherence effect serves as an optical transistor. Interference of the two output fields from the cell shows useful feature for determining the mean atomic velocity and can be useful as quantum velocimeter. We also find that the sign of the dispersive phase in EIT has a unique property, which helps to explain certain features in the interference.

Wanxia Cao, Xingda Lu, Yanhong Xiao +1 more