Light induced atomic desorption from dry-film coatings

Atomic dispensers for thermoplasmonic control of alkali vapor pressure in quantum optical applications

Alkali metal vapors enable access to single electron systems, suitable for demonstrating fundamental light-matter interactions and promising for quantum logic operations, storage and sensing. However, progress is hampered by the need for robust and repeatable control over the atomic vapor density and over the associated optical depth. Until now, a moderate improvement of the optical depth was attainable through bulk heating or laser desorption – both time-consuming techniques. Here, we use plasmonic nanoparticles to convert light into localized thermal energy and to achieve optical depths in warm vapors, corresponding to a ~16 times increase in vapor pressure in less than 20 ms, with possible reload times much shorter than an hour. Our results enable robust and compact light-matter devices, such as efficient quantum memories and photon-photon logic gates, in which strong optical nonlinearities are crucial.

Robust and fast control of the atomic vapor pressure in alkali vapor cells would greatly extend their use for many quantum technologies. Here, the authors exploit plasmonic absorption in a cell coating containing gold nanoparticles to control the vapor pressure with milliseconds response time.

Method for measuring the dwell time of spin-polarized Rb atoms on coated pyrex glass surfaces using light shift

We present a simple method for directly measuring the average dwell time of spin-polarized Rb atoms on coated Pyrex glass surfaces. The method relies on the light shift of the Zeeman resonances of spin-polarized Rb atoms pumped and probed by evanescent waves, and does not depend on the microscopic details of surface interactions. We use a cell whose length is adjustable between 70 and 500 microm. The inverse of the difference between the frequency shifts caused by sigma+ and sigma- pump beams depends linearly on the cell length, from which we obtain the average dwell time tau(s). For a Pyrex glass cell coated with octadecyltrichlorosilane we find that tau(s)=0.53+/-0.03 mus at a cell wall temperature of 103 degrees C. The temperature dependence of tau(s) is fitted to tau(s)=tau[mean](0) exp(E(a)/kT), yielding a preexponential factor tau[mean](0)=2.2(-1.4)(+5.1) ns and an activation energy E(a)=0.19+/-0.03 eV.