arXiv subjects

Adam D. West

Publications and source records attributed to Adam D. West.

7 recordsLinked to original sources

arXiv2023

Impulsive Spin-Motion Entanglement for Fast Quantum Computation and Sensing

We perform entanglement of spin and motional degrees of freedom of a single, ground-state trapped ion through the application of a $16$ ps laser pulse. The duration of the interaction is significantly shorter than both the motional timescale ($30$ $\mu$s) and spin precession timescale ($1$ ns) , demonstrating that neither sets a fundamental speed limit on this operation for quantum information processing. Entanglement is demonstrated through the collapse and revival of spin coherence as the spin components of the wavefunction separate and recombine in phase space. We infer the fidelity of these single qubit operations to be $(97^{+3}_{-4})\%$.

quant-ph↗

arXiv2019

Systematic Effects in 2D Trapped Matter-Wave Interferometers

Trapped matter-wave interferometers (TMIs) present a platform for precision sensing within a compact apparatus, extending coherence time by repeated traversal of a confining potential. However, imperfections in this potential can introduce unwanted systematic effects, particularly when combined with errors in the associated beamsplitter operations. This can affect both the interferometer phase and visibility, and can make the performance more sensitive to other experimental imperfections. I examine the character and degree of these systematic effects, in particular within the context of 2D TMIs applicable for rotation sensing. I show that current experimental control can enable these interferometers to operate in a regime robust against experimental imperfections.

physics.atom-ph↗

arXiv2016

Methods, Analysis, and the Treatment of Systematic Errors for the Electron Electric Dipole Moment Search in Thorium Monoxide

We recently set a new limit on the electric dipole moment of the electron (eEDM) (J. Baron et al., ACME collaboration, Science 343 (2014), 269-272), which represented an order-of-magnitude improvement on the previous limit and placed more stringent constraints on many CP-violating extensions to the Standard Model. In this paper we discuss the measurement in detail. The experimental method and associated apparatus are described, together with the techniques used to isolate the eEDM signal. In particular, we detail the way experimental switches were used to suppress effects that can mimic the signal of interest. The methods used to search for systematic errors, and models explaining observed systematic errors, are also described. We briefly discuss possible improvements to the experiment.

physics.atom-ph↗

arXiv2013

Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron

The Standard Model (SM) of particle physics fails to explain dark matter and why matter survived annihilation with antimatter following the Big Bang. Extensions to the SM, such as weak-scale Supersymmetry, may explain one or both of these phenomena by positing the existence of new particles and interactions that are asymmetric under time-reversal (T). These theories nearly always predict a small, yet potentially measurable ($10^{-27}$-$10^{-30}$ $e$ cm) electron electric dipole moment (EDM, $d_e$), which is an asymmetric charge distribution along the spin ($\vec{S}$). The EDM is also asymmetric under T. Using the polar molecule thorium monoxide (ThO), we measure $d_e = (-2.1 \pm 3.7_\mathrm{stat} \pm 2.5_\mathrm{syst})\times 10^{-29}$ $e$ cm. This corresponds to an upper limit of $|d_e| < 8.7\times 10^{-29}$ $e$ cm with 90 percent confidence, an order of magnitude improvement in sensitivity compared to the previous best limits. Our result constrains T-violating physics at the TeV energy scale.

physics.atom-ph↗

arXiv2012

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↗

arXiv2011

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↗

arXiv2011

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↗