Transcript The strontium project: past, present and future.

The strontium project: past,
present and future
James Millen
The team
Matt (2006)
Benjamin Pasquiou,
Sarah Mauger,
Clémentine Javaux,
Jack Snape
James (2007)
Jonny Arnold,
The tiniest slither
of Panpan Ruam
Graham (2008)
Dani (2006)
Liz Bridge (NPL) (MSci),
A little bit of Guy Corbett,
Christophe
Strontium overview – Group meeting 13/12/10
The goal
To study strontium Rydberg atoms, and ultimately
load them into an optical lattice.
Strontium overview – Group meeting 13/12/10
The goal
To study strontium Rydberg atoms, and ultimately
load them into an optical lattice.
→ Image / cool / trap Rydberg
atoms using inner valence
electron.
C. E. Simien et al.,
Phy. Rev. Lett. 92, 143001 (2004)
Strontium overview – Group meeting 13/12/10
The goal
To study strontium Rydberg atoms, and ultimately
load them into an optical lattice.
Use energy shift of inner
valence electron.
Fixed, regular and addressable.
Study charge delocalization, Mott
insulator [1], quantum simulator [2],
antiblockade [3], quantum gates [4]…
[1] M. Greiner et al. Nature 415, 39-44 (2002)
[2] H. Weimer et al. Nature Physics 6, 382-388 (2010)
[3] C. Ates et al. Phys. Rev. Lett. 98, 39-44 (2007)
[4] M. Müller et al. New J. Phys. 10, 093009 (2008)
Strontium overview – Group meeting 13/12/10
Strontium roadmap
Build a cold
strontium experiment
Two-electron
excitation
J. Millen, G. Lochead
and M. P. A. Jones
Phys. Rev. Lett 105, 213004 (2010)
Develop dispenser cell
and laser stabilization
techniques
Create a
Rydberg gas
Spatially probe
blockaded gas
E. M. Bridge, J. Millen,
C. S. Adams and M.P. A. Jones
Further cool
strontium
Rev. Sci. Instrum. 80, 013101 (2009)
C. Javaux, I. G. Hughes, G. Lochead,
J. Millen and M. P. A. Jones
Eur. Phys. J. D 57, 151-154 (2010)
Rydberg state
spectroscopy
Theory
In preparation with T. Pohl
S. Mauger, J. Millen and M. P. A. Jones
J. Phys. B: At. Mol. Opt Phys. 40, F319 (2007)
+ in preparation
Strontium overview – Group meeting 13/12/10
Study strontium Rydberg
atoms in an optical lattice
Rydberg state spectroscopy
We can detect Rydberg states due to
spontaneous ionization.
Strong inter-Rydberg
interactions
Penning ionization
This ionization process is fast (~μs) and
occurs for attractive or repulsive interactions.
Amthor et. al. Phys. Rev Lett. 98 023004 (2007)
…and/or collisions with hot atoms, black-body ionization…
Strontium overview – Group meeting 13/12/10
Rydberg state spectroscopy
Turn off trap
Create a
MOT
Measure MOT
population/density
Step Rydberg
laser frequency
Do Rydberg
excitation
Measure MOT
again
Detect ions
Strontium detective – Group meeting 19/10/09
Rydberg state spectroscopy
High spectroscopic resolution (< 2 MHz), flexible.
5s19d 1D2
2
Strontium overview – Group meeting 13/12/10
Two-electron excitation
Excitation of inner valence electron
leads to “autoionization”.
Ion
Efficient probe of
Rydberg state
population.
Strontium overview – Group meeting 13/12/10
Two-electron excitation
The inner valence electron transition has an
excitation spectrum, an “autoionization spectrum”.
5s19d 1D2
5s20s 1S0
Spectrum described with MQDT.
Shape is determined by the state of the Rydberg electron.
Strontium overview – Group meeting 13/12/10
Two-electron excitation
We used the autoionization spectrum to detect
and measure population transfer.
Fast ionization,
some electrons leave.
Positive charge binds electrons.
Electrons oscillate through gas,
l-changing collisions.
Strontium overview – Group meeting 13/12/10
After some time, only the
higher angular momentum
Rydberg states present.
What’s next?
What effect does the dipole blockade have on
ensembles of atoms?
Use a focused beam to autoionize
the Rydberg sample.
Strontium overview – Group meeting 13/12/10
And then?
Further cool and load into a lattice.
56D + 56D
Blue MOT: ~5mK
Red MOT: ~400nK
Strontium overview – Group meeting 13/12/10