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:20230610T015144Z
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.

\n

\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 ^{87}Rb gas. The absorption
profile of a weak probe laser beam on 5*S*_{1/2} â†’ 5*P*_{3/2} transition is observed in the presence of a stron
g coupling laser beam at 480 nm driving the 5*P*_{3/2} â†
’ *nD*_{5/2} transition for the Rydberg states with princ
ipal quantum numbers in the range 20â‰¤*n*â‰¤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*.

\n

\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.

\n

\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
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