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Kevin J. Weatherill

Publications and source records attributed to Kevin J. Weatherill.

23 records · Page 2Linked to original sources

Three-photon electromagnetically induced transparency using Rydberg states

We demonstrate electromagnetically induced transparency (EIT) in a four-level cascade system where the upper level is a Rydberg state. The observed spectral features are sub-Doppler and can be enhanced due to the compensation of Doppler shifts with AC Stark shifts. A theoretical description of the system is developed which agrees well with the experimental results and an expression for the optimum parameters is derived.

physics.atom-ph↗

Piezoelectrically-actuated time-averaged atomic microtraps

We present a scheme for creating tight and adiabatic time-averaged atom-traps through the piezoelectric actuation of nanomagnetic structures. We show that potentials formed by the circular translation of magnetic structures have several advantages over conventional rotating-field techniques, particularly for high trap frequencies. As the magnitude of the actuation is changed the trapping potential can be changed adiabatically between harmonic 3D confinement and a toroidal trap.

physics.atom-ph↗

Manipulating ultracold atoms with a reconfigurable nanomagnetic system of domain walls

The divide between the realms of atomic-scale quantum particles and lithographically-defined nanostructures is rapidly being bridged. Hybrid quantum systems comprising ultracold gas-phase atoms and substrate-bound devices already offer exciting prospects for quantum sensors, quantum information and quantum control. Ideally, such devices should be scalable, versatile and support quantum interactions with long coherence times. Fulfilling these criteria is extremely challenging as it demands a stable and tractable interface between two disparate regimes. Here we demonstrate an architecture for atomic control based on domain walls (DWs) in planar magnetic nanowires that provides a tunable atomic interaction, manifested experimentally as the reflection of ultracold atoms from a nanowire array. We exploit the magnetic reconfigurability of the nanowires to quickly and remotely tune the interaction with high reliability. This proof-of-principle study shows the practicability of more elaborate atom chips based on magnetic nanowires being used to perform atom optics on the nanometre scale.

physics.atom-ph↗

Nanomagnetic engineering of the properties of domain wall atom traps

We have used the results of micromagnetic simulations to investigate the effects of nanowire geometry and domain wall magnetization structure on the characteristic parameters of magnetic atom traps formed by domain walls in planar ferromagnetic nanowires. It is found that when traps are formed in the near-field of a domain wall both nanowire geometry and wall structure have a substantial effect on trap frequency and adiabaticity. We also show that in certain regimes a trap's depth depends only on the amplitude of an externally applied rotating magnetic field, thus allowing it to be tuned independently of the trap's other critical parameters.

physics.atom-ph↗

Polarization spectroscopy of an excited state transition

We demonstrate polarization spectroscopy of an excited state transition in room temperature cesium vapor. An anisotropy induced by a circularly polarized pump beam on the D2 transition is observed using a weak probe on the 6P3/2 to 7S1/2 transition. When the D2 transition is saturated, a sub-natural linewidth feature is observed which theoretical modeling shows is enhanced by Doppler averaging. Polarization spectroscopy provides a simple modulation-free signal suitable for laser frequency stabilization to excited state transitions.

physics.atom-ph↗