Dynamical Realization of Macroscopic Superposition States of Cold Bosons in a Tilted Double Well

We present exact expressions for the quantum sloshing of Bose-Einstein condensates in a tilted two-well potential. Tunneling is suppressed by a small potential difference between wells, or tilt. However, tunneling resonances occur for critical values of the tilt when the barrier is high. At resonance, tunneling times on the order of 10-100 ms are possible. Furthermore, such tilted resonances lead to a dynamical scheme for creating few-body NOON-like macroscopic superposition states which are protected by the many body wavefunction against potential fluctuations.Comment: 6 pages, 5 figures, final version, only minor changes from previous arXiv versio

Observation of a Large Atomic Parity Violation Effect in Ytterbium

Atomic parity violation has been observed in the 6s^2 1S0 - 5d6s 3D1 408-nm forbidden transition of ytterbium. The parity-violating amplitude is found to be two orders of magnitude larger than in cesium, where the most precise experiments to date have been performed. This is in accordance with theoretical predictions and constitutes the largest atomic parity-violating amplitude yet observed. This also opens the way to future measurements of neutron skins and anapole moments by comparing parity-violating amplitudes for various isotopes and hyperfine components of the transition

Measurement of dynamic Stark polarizabilities by analyzing spectral lineshapes of forbidden transitions

We present a measurement of the dynamic scalar and tensor polarizabilities of the excited state 3D1 in atomic ytterbium. The polarizabilities were measured by analyzing the spectral lineshape of the 408-nm 1S0->3D1 transition driven by a standing wave of resonant light in the presence of static electric and magnetic fields. Due to the interaction of atoms with the standing wave, the lineshape has a characteristic polarizability-dependent distortion. A theoretical model was used to simulate the lineshape and determine a combination of the polarizabilities of the ground and excited states by fitting the model to experimental data. This combination was measured with a 13% uncertainty, only 3% of which is due to uncertainty in the simulation and fitting procedure. The scalar and tensor polarizabilities of the state 3D1 were measured for the first time by comparing two different combinations of polarizabilities. We show that this technique can be applied to similar atomic systems.Comment: 13 pages, 7 figures, submitted to PR

Control of atomic currents using a quantum stirring device

We propose a BEC stirring device which can be regarded as the incorporation of a quantum pump into a closed circuit: it produces a DC circulating current in response to a cyclic adiabatic change of two control parameters of an optical trap. We demonstrate the feasibility of this concept and point out that such device can be utilized in order to probe the interatomic interactions.Comment: 5 pages, 4 figures, uses epl2.cls, revised versio

Atomic parity violation in 0-to-0 two-photon transitions

We present a method for measuring atomic parity violation in the absence of static external electric and magnetic fields. Such measurements can be achieved by observing the interference of parity conserving and parity violating two-photon transition amplitudes between energy eigenstates of zero electronic angular momentum. General expressions for induced two-photon transition amplitudes are derived. The signal-to-noise ratio of a two-photon scheme using the 6s^2 1S0 to 6s6p 3P0 transition in ytterbium is estimated.Comment: 8 pages, 2 figures, submitted to PR