BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-3547 DTSTART:20141217T160000Z DURATION:PT1H0M0S DTSTAMP:20260419T161527Z LAST-MODIFIED:20141203T144353Z LOCATION:5310 Chamberlin hall SUMMARY:Application of mesoscopic atomic ensembles with random number of atoms to quantum information and quantum optics\, Atomic Physics Se minar\, Ilya Beterov\, Rzhanov Institute of Semiconductor Physics :Nov osibirsk State University: Novosibirsk\, Russia DESCRIPTION:Mesoscopic ensembles of ultracold interacting atoms can be implemented by loading the cold atoms into an optical dipole trap. Th ese ensembles are of interest for encoding of quantum information\, ge neration of collective entangled states and observation of cooperative effects in atom-light interactions. Long-range interactions between t he atoms in the ensemble lead to the effect of Rydberg blockade when n ot more than one atom could be excited into a Rydberg state by a narro w-band laser radiation.
\nThe number of atoms in the trap is rand om and is commonly described by the Poissonian statistics. In the regi me of Rydberg blockade an atomic ensemble\, which consists of N atoms\ , can be treated as a two-level system with enhanced coupling to the l aser radiation field by a factor of compared to a single atom. A sin gle Rydberg excitation is shared between all atoms in the ensemble. Fl uctuations of the frequency of Rabi oscillations between the collectiv e states of the atomic ensembles can result in collapses and revivals of Rabi oscillations\, similarly to Jaynes-Cummings model in quantum o ptics. These fluctuations can also lead to significant errors in quant um information processing. We have proposed to use the adiabatic passa ge in atomic ensembles for deterministic single-atom excitation and qu antum logic gates in ensembles with unknown numbers of atoms. The doub le adiabatic sequences provide deterministic single-atom Rydberg excit ation and remove the accumulation of undesirable dynamic phase. This c an be used to implement quantum gates on collectively encoded qubits w ithout precise knowledge of N.
\n URL:https://www.physics.wisc.edu/events/?id=3547 END:VEVENT END:VCALENDAR