RESUMEN
We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 µs with an overall detection efficiency η exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing channel electron multipliers. The scheme enables the calibration of absolute detection efficiencies and might be a key ingredient for future quantum information applications or precision spectroscopy of ultracold atoms.
RESUMEN
A radiation furnace that covers the temperature range from room temperature up to 1800 K has been designed and constructed for in situ synchrotron microtomography. The furnace operates under a vacuum or under any inert gas atmosphere. The two 1000 W halogen heating lamps are water- and air-cooled. The samples are located at the focus of these lamp reflectors on a rotary feedthrough that is connected to a driving rotation stage below the furnace. The X-ray beam penetrates the furnace through two X-ray-transparent vacuum-sealed windows. Further windows can be used for temperature control, sample changing and gas inflow and outflow.
Asunto(s)
Tomografía/instrumentación , Diseño de Equipo , Calor , Microscopía Electrónica de Rastreo , Sincrotrones , Rayos XRESUMEN
We report the observation of entanglement between a single trapped atom and a single photon at remote locations. The degree of coherence of the entangled atom-photon pair is verified via appropriate local correlation measurements, after communicating the photon via an optical fiber link of 300 m length to a receiver 3.5 m apart. In addition, we measured the temporal evolution of the atomic density matrix after projecting the atom via a state measurement of the photon onto several well-defined spin states. We find that the state of the single atom dephases on a time scale of 150 micros, which represents an important step towards long-distance quantum networking with individual neutral atoms.
RESUMEN
The fixing shoe with rolling sole (arthrodesis shoe) serves to ensure pain-free or at least tolerably painless walking in case of changes due to arthrosis or lesion sequelae in the ankle joints or the tarsus. This is achieved by means of a high shaft of adequate strength, an accurate bedding of the foot, and a rolling sole with sufficient lift at the tip. This shoe is indicated in cases where the load alone is well tolerated whereas load in conjunction with movement produces pain. Several types of these orthopedic shoes have been developed. Of these, the model with interchangeable built-in element has proved most successful in the authors' experience. This built-in element consists of a drummed (milled) cap reinforced with cast resin, and a cork bedding. This removable or interchangeable unit is advantageous compared with a firmly integrated system insofar as any changes or repairs can be effected easily and at a lower cost.