We demonstrate confinement of $^{85}\mathrm{Rb}$ atoms in a dark, toroidal optical trap. use spatial light modulator to convert single blue-detuned Gaussian laser beam superposition Laguerre-Gaussian modes that forms ring-shaped intensity null bounded harmonically all directions. measure $1∕e$ spin-relaxation lifetime $\ensuremath{\approx}1.5\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ for trap detuning $4.0\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. For smaller detunings, time-dependent relaxation...

We introduce an adaptive optical refinement method enabling ultra-precise micro-milling of arbitrary surfaces. Through repeated iteration, our reduces surface error without requiring significant specific engineering. This remediates the long sample preparation times and lack capability that previously reported methods suffer from. The iterative milling was used to produce spherical mirrors with small radii curvature low roughness for use in micro Fabry-Perot cavities. demonstrate this...

We demonstrate a two-dimensional (2D) grating magneto-optical trap (GMOT) with single input cooling laser beam and planar diffraction using $^{87}\mathrm{Rb}$. This configuration increases experimental access when compared traditional 2D (MOT). As described in the paper, output flux is several hundred million rubidium atoms/s at mean velocity of 16.5(9) m/s distribution 4(3) standard deviation. use atomic from GMOT to loading three-dimensional (3D)...

The mechanical behavior of cells offers insight into many aspects their properties. We propose an approach to the analysis that uses a combination electromanipulation for stimulus and capacitance sensing. To demonstrate this approach, polystyrene spheres yeast flowing in 25 mumx100 mum microfluidic channel were detected by perpendicular pair gold thin film electrodes channel, spaced apart. presence was changes between electrodes. sensor resonant coaxial radio frequency cavity (2.3 GHz)...

We demonstrate the continuous injection and propagation of a cold atomic beam in high-gradient (up to $2.7\phantom{\rule{0.3em}{0ex}}\mathrm{kG}∕\mathrm{cm}$) magnetic guide $1.7\phantom{\rule{0.3em}{0ex}}\mathrm{m}$ length. Continuous is accomplished using side-loading scheme that involves sequence two modified magneto-optic traps. Methods are developed measure atomic-flow temperatures flux under steady-state conditions. In portion guide, guided has transverse temperature...

Ex vacuo atom chips, used in conjunction with a custom thin walled vacuum chamber, have enabled the rapid replacement of chips for magnetically trapped cold experiments. Atoms were >2 kHz magnetic traps created using high power chips. A chamber allowed atoms to be ≲1 mm from chip conductors which located outside system. Placing simplified electrical connections and improved thermal management. Using multi-lead Z-wire design, Bose-Einstein condensate was produced an external chip....

We report the fabrication, characterization, and use of rubidium vapor dispensers based on highly-oriented pyrolytic graphite (HOPG) intercalated with metallic rubidium. Compared to commercial chromate salt dispensers, these HOPG (IHOPG) hold an order magnitude more in a similar volume, require less than one-fourth heating power, emit one-half as many impurities. Appropriate processing permits exposure IHOPG atmosphere for over ninety minutes without any adverse effects. Intercalation cesium...

We have observed time-varying spin relaxation of trapped cold atoms due to photon scattering in blue-detuned, crossed, hollow Laguerre-Gaussian beams. These beams are formed by imparting an azimuthal phase $\ensuremath{\ell}\ensuremath{\varphi}$ a Gaussian beam, where $\ensuremath{\ell}$ is integer, and intensity distribution that scales with ${r}^{2\ensuremath{\ell}}$ the lowest order. For all degrees anharmonicity, we observe spin-relaxation rate energy-dependent scattering....

We demonstrate a method for increasing the amount of power available laser cooling applications by using multimode optical fiber. Through randomization phase shifts modes within fiber on time scales faster than center-of-mass response atoms, smooth time-averaged trapping beam is generated. The principle has been demonstrated in pyramidal magneto-optical trap. particularly suitable harnessing high output broad-area diode lasers cooling.

We observe velocity-selective two-photon resonances in a cold atom cloud the presence of magnetic field. use these to demonstrate simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing field and does not require any additional laser frequencies than are already used standard magneto-optical traps. verify effects using Faraday rotation spectroscopy.

We present a method for generating precise magnetic potentials that can be described by polynomial series along the axis of cold atom waveguide near surface an chip. With single chip design consisting several wire pairs, various axial created varying ratio currents in wires, including double wells, triple and pure harmonic traps with suppression higher order terms. use this to fabricate modest experimental requirements. Finally, we demonstrate well potential.

We study steady-state evaporation in an atom guide via Monte Carlo simulations. The surface follows a specific profile as function of longitudinal location. demonstrate that the choice significantly impacts performance evaporation. Our simulations also significant boost when using longitudinally compressed guide. show for purely pressure-driven beam, it should be possible to reach degeneracy within $0.5~\m$ experimentally feasible, albeit challenging, loading conditions.

This paper reports on radio frequency (RF) sources that have been virtually-prototyped with the Improved Concurrent Electromagnetic Particle-in-Cell (ICEPIC) code. ICEPIC simulates from first-principles, Maxwell's equations and Lorenz's force law, electrodynamics charged particle dynamics of RF-producing part system. Our simulations focus several proposed variants L-band A66 half height (A66-hh) relativistic magnetron HPM source. The variations A66-hh include higher designs (C-band, S-band...

Received 2 October 2017DOI:https://doi.org/10.1103/PhysRevA.96.049902©2017 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAtom interferometryAtom lasersAtom opticsBose-Einstein condensatesCold atoms & matter wavesCooling trappingAtomic, Molecular Optical

A device sensing the change in capacitance as single cells flow through a microfluidic channel past interdigitated electrodes is described. 0.45 aF resolution within 3 ms time constant has been achieved. cellpsilas electrical properties can vary greatly due to ionic currents, double layer effects, and membrane potential gradients (particularly when operating below 200 MHz). Sensing at microwave frequencies (1.6 GHz) reduces these effects. Cells are simultaneously actuated by superimposing...

We calculate the sensitivity to changes in temperature and current for a resonant atom interferometer device based on oscillations of cold, magnetically trapped cloud two wire harmonic trap. The trap frequency area enclosed are estimated typical parame- ters. Based this analysis, both more sensitive stability creating magnetic eld than thermal expansion substrate. Current experimental progress measuring chip devices is outlined.