Advances in the preparation and detection, but most importantly in the coherent manipulation of single neutral atoms have allowed the observation of intriguing phenomena of quantum physics in recent years. We discuss developments to prepare and detect single neutral atoms in a one-dimensional optical lattice potential with single site resolution. Moreover, using two different experimental techniques, a state-dependent optical lattice potential on the one hand and a high-finesse optical cavity on the other hand, we have obtained coherent control over single neutral atoms. The former has enabled us to observe the quantum walk of atoms in position space, and to coherently control the motion of trapped atoms via microwave radiation. The latter offers a means to non-destructively detect the atomic spin state, thereby revealing quantum jumps of single atoms, or the altered optical properties of single atoms when subject to electromagnetically-induced transparency.
We theoretically study the cyclotron dynamics of ultra-cold atoms in optical lattices exposed to an artificial magnetic field. The cyclotron orbit and its stability are discussed both analytically and numerically. We find that the cyclotron dynamics of atoms in optical lattices can be manipulated by adjusting the strength of the magnetic field. Atoms can be coherently localized in its initial position, or can be trapped in a priori prescribed orbit doing coherent cyclotron motion, or can be decoherently diffused with time. The stability of the orbit and the coherence of the system present asymmetric characters. Our results provide a direct theoretical evidence for the cyclotron dynamics of neutral atoms in the artificial magnetic field.
Spin-dependent optical potentials allow us to use microwave radiation to manipulate the motional state of trapped neutral atoms (Förster et al 2009 Phys. Rev. Lett. 103 233001). Here, we discuss this method in greater detail, comparing it to the widely employed Raman sideband coupling method. We provide a simplified model for sideband cooling in a spin-dependent potential, and we discuss it in terms of the generalized Lamb–Dicke parameter. Using a master equation formalism, we present a quantitative analysis of the cooling performance for our experiment, which can be generalized to other experimental settings. We additionally use microwave sideband transitions to engineer motional Fock states and coherent states, and we devise a technique for measuring the population distribution of the prepared states.