Engineering topics

Chwedenczuk, Jan

Publications and source records attributed to Chwedenczuk, Jan.

2 records

DOE OSTI2010

Phase estimation with interfering Bose-Einstein-condensed atomic clouds

We investigate how to estimate from atom-position measurements the relative phase of two Bose-Einstein condensates released from a double-well potential. We demonstrate that the phase-estimation sensitivity via the fit of the average density to the interference pattern is fundamentally bounded by shot noise. The shot noise can be overcome by estimating the phase from the measurement of order {radical}(N) (or higher) correlation functions. The optimal estimation strategy, saturating the quantum Fisher information, requires the measurement of the Nth-order correlation function. We demonstrate that a different estimation method--based on the detection of the center of mass of the interference pattern--also provides sub-shot-noise sensitivity. The implementation of both protocols, however, might be experimentally challenging.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2010

Rabi interferometry and sensitive measurement of the Casimir-Polder force with ultracold gases

We show that Rabi oscillations of a degenerate fermionic or bosonic gas trapped in a double-well potential can be exploited for the interferometric measurement of external forces at micrometer length scales. The Rabi interferometer is less sensitive but easier to implement than the Mach-Zehnder, since it does not require dynamical beam-splitting or recombination processes. As an application we propose a measurement of the Casimir-Polder force acting between the atoms and a dielectric surface. We find that even if the interferometer is fed with a coherent state of relatively small number of atoms, and in the presence of realistic experimental noise, the force might be measured with a sensitivity sufficient to discriminate between thermal and zero-temperature regimes of the Casimir-Polder potential. Higher sensitivities can be reached with bosonic spin squeezed states.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗