Mallory Traxler April 2013

murmerlastUrban and Civil

Nov 16, 2013 (3 years and 8 months ago)

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Mallory
Traxler

April 2013

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Continuous atom laser


Continuous, coherent stream of atoms


Outcoupled

from a BEC


Applications of atom lasers:


Atom interferometry


Electromagnetic fields


Gravitational fields


Precision measurement gyroscopes


Atom lithography

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Guide
α


Experimental apparatus


Experiments in guide
α


Rydberg atom guiding


Design and manufacture of guide
β


Improvements from guide
α
’s design


Outlook

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α

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α

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Φ
pmot
≈3x10
9

s
-
1


<
v
z,pmot
>
≈22 m/s






2D+ MOT


Φ
mmot
≈4.8x10
8

s
-
1


2.2 m/s to 2.9 m/s






cos
)
(


v
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Detect atoms at the end


Uses pulsed probe (2

3) and probe
repumper

(1

2)


Optimize atoms in the guide


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Three lasers for excitation


Repumper

to get back to
bright state


5S
1/2

5P
3/2



480 nm to 59D


Ionize


Voltages on electrode,
guard tube, MCP direct
ions upward to MCP for
detection

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α

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High n
-
principal quantum number


Data here with n=59


Physically large


r~n
2


Very susceptible to electric fields


α
~n
7


Strong interactions


Other Rydberg atoms


Blackbody radiation

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Excitation to 59D


Variable delay time, t
d


MI or FI


Camera gated over ionization duration

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Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Penning ionization


Remote field ionization


Initial


delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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/39


Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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/39


Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Penning ionization


Remote field ionization


Initial


Delayed


Thermal ionization


(
Radiative

decay)


Microwave ionization


Field ionization


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Vary t
d

from
5
μ
s to 5 ms


τ
MI
=700
μ
s


τ
59D5/2
=150
μ
s

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State
-
selective field
ionization


Different electric field
needed for different
states


59D peak broadens


State mixing


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Rydberg atoms excited from ground state
atoms trapped in guide


Observe Rydberg guiding over several
milliseconds

using microwave ionization and
state selective field ionization


Numerous phenomena from Rydberg atoms
within the guide

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β

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Improvements over guide
α


Zeeman slower


No launching


Magnetic injection


Mechanical shutter


β

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Standard 6
-
beam MOT


Fed by Zeeman slower


Factor of 6.6 brighter


Expect closer to 10x

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Most complicated part
of the design


4 racetrack 2MOT coils


8 injection coils


Built
-
in water cooling


Magnetic compression


Mechanical shutter

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4 racetrack coils
produce
quadrupole

magnetic field


Holes


Optical access


Venting of internal
parts


Shutter


2 locks for
stationary shutter

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8 injection coils of
varying diameters


Fits inside 2MOT coil
package


Water cooling for all


Tapered inside and out

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Magnetic compression


Mount for
waveplate
-
mirror


Stationary shutter

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Hand
-
turned on lathe


2MOT coils on form


Injection coils directly on
mount


Labeled with UHV
compatible ceramic
beads

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High current power supply


Split off 2
-
3 A for each coil


Adiabatically inject atoms
into the guide

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21 equally spaced silicon
surfaces


Bring guided atomic flow
closer to these surfaces


Atoms not adsorbed onto
surface
rethermalize

at lower
temperature

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Fully constructed


Preliminary tests well on the way


Good transfer of atoms into the 2MOT


Need Zeeman slower and 2MOT working
simultaneously to optimize

β

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Increase capture volume of Zeeman slower


Reduce transverse velocity by factor of x,
increase density by factor of x
2


Most optics already in place

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Potential barrier at the end of the guide


Form BEC upstream


Use coil to create potential


Study BEC loading dynamics, number fluctuations


Later use light shield barrier


Tunnel atoms through to make first continuous
atom laser

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PI


Prof. Georg
Raithel



Former Post Docs


Erik Power


Rachel
Sapiro



Former Grad Students


(on this project)


Spencer Olson


Rahul

Mhaskar


Cornelius
Hempel



Recent Ph.D.


Eric
Paradis








Graduate Students


Andrew
Cadotte


Andrew Schwarzkopf


David Anderson


Kaitlin Moore


Nithiwadee

Thaicharoen


Sarah Anderson


Stephanie Miller


Yun
-
Jhih

Chen



Current Undergraduate


Matt
Boguslawski



Former Undergrads


Varun

Vaidya


Steven Moses


Karl Lundquist





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