Biomedical subjects

G Raithel

Publications and source records attributed to G Raithel.

12 recordsLinked to original sources

PubMed2002

Tunneling resonances and coherence in an optical lattice.

The center-of-mass quantization of atoms trapped in a gray optical lattice is observed to manifest itself in the steady-state properties of the atoms. Modulations in the lifetime and macroscopic magnetization as a function of an applied B field are attributed to quantum mechanical tunneling resonances and are shown to exist only under conditions which afford spatial coherence of the trapped atoms over several lattice wells and coherence times that exceed the tunneling period.

Journal Article↗

PubMed2002

Feedback control of atomic motion in an optical lattice.

We demonstrate a real-time feedback scheme to manipulate wave-packet oscillations of atoms in an optical lattice. The average position of the atoms in the lattice wells is measured continuously and nondestructively. A feedback loop processes the position signal and translates the lattice potential. Depending on the feedback loop characteristics, we find amplification, damping, or an entire alteration of the wave-packet oscillations. Our results are well supported by simulations.

Journal Article↗

PubMed2001

High-angular-momentum states in cold Rydberg gases.

Cold, dense Rydberg gases produced in a cold-atom trap are investigated using spectroscopic methods and time-resolved electron counting. Optical excitation on the discrete Rydberg resonances reveals long-lasting electron emission from the Rydberg gas ( >20 ms). Our observations are explained by lm-mixing collisions between Rydberg atoms and slow electrons that lead to the population of long-lived high-angular-momentum Rydberg states. These atoms thermally ionize slowly and with large probabilities.

Journal Article↗

PubMed2000

Ponderomotive optical lattice for Rydberg atoms.

We propose to use the ponderomotive energy of Rydberg electrons in standing-wave light fields to form an optical lattice for Rydberg atoms. Application of the Born-Oppenheimer approximation shows that, with readily achievable experimental parameters, atoms in any Rydberg state can be trapped. Realization of this scheme would extend the benefits of atom trapping to highly excited atoms.

Journal Article↗

PubMed1995