BEGIN:VCALENDAR VERSION:2.0 PRODID:Data::ICal 0.22 BEGIN:VEVENT DESCRIPTION:Dr. Charles Brown II \, University of California\, Berkeley\n\n
The unique proper ties of superfluid 4He (low mechanical stiffness\, zero viscosi ty\, high structural and chemical purity and extremely low optical loss) m ay allow the direct pursuit of optomechanics with quantum mechanical oscil lators. We have constructed an optomechanical system consisting entirely o f a magnetically levitated drop of superfluid 4He in vacuum. Le vitation removes a source of loss associated with physically clamped oscil lators. and allows the drop to efficiently cool itself via evaporation. Th e drop&rsquo\;s optical whispering gallery modes (WGMs) and its surface vi brations couple to each other via the usual optomechanical interactions. W e demonstrate the stable magnetic levitation of superfluid 4He drops in vacuum\, and present measurements of the drops'\; evaporation rates\, temperatures\, optical modes and surface vibrations. We found opti cal modes with finesse &asymp\;40 \;(limited by the drop'\;s size). We found surface vibrations with decay rates &sim\;1 \;Hz (in rough agreement with theory). La stly\, we found that the drops reach a temperature T&asymp\;330 \;mK\, and that a singl e drop can be trapped indefinitely.
\n DTSTART:20201002T193000Z LOCATION:online\, Room via Zoom SUMMARY:Isolated Superfluid Liquid Helium Drops in a Magneto-Gravitational Trap END:VEVENT END:VCALENDAR