Transcript Quantum Effects on Rubidium - Materials Science Institute

Laser Optics
and
Quantum Mechanics
Jason Goff, UCORE Summer ‘07
Steck Lab, University of Oregon
Oregon Center for Optics
Overall Goals

Currently, the table is being tuned to
allow for dipole operation. However, the
Magneto-Optical Trap (MOT) is
operating as designed.
– Short term goals would include a one-way
barrier
– Long term goals include Quantum
feedback control, measurement, Chaos,
and Quantum to classical transitions
Table Lay-out

The table is
arranged with a
MOT and a dipole
trap. Of the two,
the MOT is the one
that has a
magnetic coil
assembly.
Visible “MOT” in Hellma Cell with AH coils
visible above and below the cell
assembly (courtesy of Steck Lab).
Quantum Mechanisms

MOT
– Considered by the
communitee to be the general
workhorse for quantum
experimentation.
– Uses 6 lasers with optics to
create a focus in the center of
Hellma Cell. These beams
can be emitted by multiple
lasers or by one laser and
split via a beam splitter.
– In tandem to the lasers are
two coils called
AntiHelmholtz Coils. These
work in concert to ensure
that the 87Rb is collected in
the center of the Hellma cell
for sampling and testing.
• Not as effective as a dipole
trap for experimental testing
Courtesy of Steck Lab
MOT arrangement

These pictures demonstrate
the arrangement of the MOT
assembly; the circles being
the AH coil, the 6 red arrows
signifying the laser beam
trajectory to the center, and
then the blue dot which
signifies the trapped element
(in this case, 87Rb).
AH Driver Board

An Anti-Helmholtz driver board
completely “stuffed” and ready to
use.
–

Has two different voltage circuits,
a 15V circuit for running the
board and a 40V circuit for
running the coils.
Boards are designed to run a
single coil and operate in tandem
as a Master-Slave system.
–
The master board controls the
current control to the coils while
the slave control adjusts the gain
of the slave coil, i.e. the difference
current through each coil.
• The optimal gain is 1:1
Pictures courtesy of Jeremy thorn
UCORE Contribution

Upon arrival in to the Steck lab, I was assigned the task of
diagnosing a laser voltage supply board. However, due to
the enormous task and my lack of experience, it was
decided that I should build and test Anti-Helmholtz driver
boards.
–

This task would give me the necessary skills to understand future projects which
might need electronics or a circuit background.
UCORE made possible the construction of 3 separate boards as well as
other minor equipment additions.
Sources and Acknowledgements




Pictures courtesy of Steck lab, University of Oregon
Thanks to Dan Steck, University of Oregon
Phillips, William D. (1998): Laser cooling and trapping of
neutral atoms, in: Reviews of Modern Physics 3 / 70, S. 721741.
Steck, Daniel A (2006): Classical and Modern Optics, Class
Notes, pg 207-227.
Research made possible by grants from the NSF and UCORE