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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-3616
DTSTART:20150128T220000Z
DTEND:20150128T230000Z
DTSTAMP:20260419T153856Z
LAST-MODIFIED:20150123T224528Z
LOCATION:4274 Chamberlin Hall
SUMMARY:Quantum control of atoms\, ions\, and nuclei \, R. G. Herb Con
densed Matter Seminar\, Christian Schneider\, UCLA
DESCRIPTION:Cold atoms and ions provide an interesting playground for
a
\nvariety of measurements of fundamental physics. Using RF trap
s\, experiments
\nbecome possible with both large ensembles of ion
s\, e.g. in cold chemistry\, and
\nfew/single ions\, such as in qu
antum computations/simulations or optical clocks\,
\nwhere ultimat
e quantum control is required. In the first part of the talk\,
\n
recent results from our work on cold chemistry and cold molecular ions
using a
\nhybrid atom--ion experiment will be presented. We have
developed an integrated
\ntime-of-flight mass spectrometer\, whic
h allows for the analysis of the complete
\nion ensemble with isot
opic resolution. Using this new setup\, we have
\nsignificantly e
nhanced previous studies of cold reactions in our
\nsystem. Poten
tial routes towards ultra-cold reactions at the quantum level
\nwi
ll be presented. Current work aims at demonstrating rotational coolin
g of
\nmolecular ions and photo-associating molecular ions.
\n
\nThe second part of the talk reports on our results of the searc
h for the
\nlow-energy isomeric transition in thorium-229. This t
ransition in the
\nvacuum-ultraviolet regime (around 7.8 eV) has a
lifetime of tens of
\nminutes to several hours and is better isol
ated from the environment
\nthan electronic transitions. This mak
es it a very promising
\ncandidate for future precision experiment
s\, such as a nuclear clock or tests of
\nvariation of fundamental
constants\, which could outperform implementations
\nbased on ele
ctronic transitions. Our approach of a direct search for the
\nnu
clear transition uses thorium-doped crystals and\, in a first experime
nt\,
\nsynchrotron radiation (ALS\, LBNL) to drive this transition
. We were able to
\nexclude a large region of possible transition
frequencies and lifetimes.
\nCurrently\, we continue our efforts
with enhanced sensitivity using a pulsed VUV
\nlaser system.
\
n
URL:https://www.physics.wisc.edu/events/?id=3616
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