BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-2033 DTSTART:20101207T170000Z DURATION:PT1H0M0S DTSTAMP:20260506T161414Z LAST-MODIFIED:20101202T224909Z LOCATION:5280 Chamberlin SUMMARY:Measurement of the dipole moment for transitions to Rydberg st ates in ultracold rubidium\, Atomic Physics Seminar\, Michal Piotrowic z\, The Open University\, Milton Keynes UK DESCRIPTION:Dipole matrix elements are required for calculations of nu merous spectroscopic properties of excited atoms including oscillator strengths\, polarisabilities and radiative lifetimes. There is no exac t analytical solution for the calculation of radial matrix elements fo r alkali atoms\, however many theoretical models have been developed t hat include numeric integration of Schroedinger's equation in the Coul omb approximation with quantum defects taken as input parameters or us ing various model potentials. In quasiclassical methods the radial mat rix elements are calculated avoiding the direct numerical integration using transcendental functions. Despite the large number of existing t heoretical models\, lack of experimental data on dipole matrix element s for rubidium complicates their verification.
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\nIn my talk I will present the experimental setup built at The Open University\, UK to investigate the ultracold Rydberg atoms. I will show our first r esults of the measurements of the dipole moments for the transitions t o the Rydberg states by investigation of the electromagnetically induc ed transparency (EIT) in ultracold 87Rb gas. The absorption profile of a weak probe laser beam on 5S1/2 → 5P3/2 transition is observed in the presence of a stron g coupling laser beam at 480 nm driving the 5P3/2 ↠’ nD5/2 transition for the Rydberg states with princ ipal quantum numbers in the range 20≤n≤48. The strong depen dence of the shape of the EIT spectrum on the Rabi frequency of the tr ansition between the first excited state and Rydberg states allowed us to directly measure the dipole moments of the transitions involved fo r several values of principal number n.
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\nThe dipole matrix elements for transitions measured in our experiment are compar ed with theoretical methods including quasiclassical calculations base d on Dyachkov-Pankratov model\, and Coulomb approximations. A very goo d agreement with the theoretical calculations is observed.
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\nI will conclude the talk with the outline of further projects with u ltracold Rydberg atoms that are carried out at the Open University. \n URL:https://www.physics.wisc.edu/events/?id=2033 END:VEVENT END:VCALENDAR