bose-einstein condensation in microgravity
TRANSCRIPT
Bose-Einstein Condensation in Microgravity
S. T. Seidel, Institute of Quantum Optics, Leibniz University of Hanover
Page 2S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Motivation: Microgravity
2Takacc ××=Drr
j
22 TAmAtomrot µW×=D
rr
hj
Sagnac Interferometer
a
W Sensitivity:
§ Extended time of evolution
T
Page 3S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Motivation: BEC
§ Slower free expansion compared to ultra-cold thermal atoms§ Coherent source
BECBEC
Slowing the free expansion by lowering thetrap depth before release of the condensate
Less interaction and potential energyconverted into kinetic energy
Page 4S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The drop tower Bremen
Platform µg-Quality [g] µg-Duration
ISS 10-4 days to months
Space carrier 10-6 3 days
Parabola flights 10-2 20 seconds
Ballistic rockets 10-5 6 minutes
Drop tower 10-6 4.8 s, x 2 with catapult
Page 5S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The drop tower Bremen
§ Free fall: 4.8 s
§ Residual acceleration:
10-5 m/s2 below 100 Hz
§ 3 flights per day
§ Capsule decelerationup to 500 m/s2
§ Strict requirements:
§ Dimensions < 0.6 Æ
x 1.73 m
§ Payload < 234 kg
Page 6S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The QUANTUS Experiment
286 cm
20 cm
Page 7S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Principles of an atom chip: Chip MOT
Page 8S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Experimental Sequence loading phase: 1.1 x 107 atoms in the MOT
temperature: 230 µKloading time: 4,2 s
chip-MOT: 6.5 x 107 atomstemperature: 230 µK
positioning of the trap in 20 ms
molassis phase: cooling down to 15 µK
5.0 x 106 atomsdetuning (29,0 ± 0,4) MHz
Page 9S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
loading phase: 1.1 x 107 atoms in the MOT
temperature: 230 µKloading time: 4,2 s
chip-MOT: 6.5 x 106 atoms temperature: 230 µK
positioning of the trap in 20 ms
molasses phase: cooling down to 15 µK
5.0 x 106 atomsdetuning (29,0 ± 0,4) MHz
magnetic trap: 4,5 x 106 atomstemperature: 25 µK
Experimental Sequence
Page 10S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Bose-Einstein Condensate in Microgravity
50 ms
500 ms
1000 ms
1400 µm
§ Over 180 drops
§ Studied the evolution of theoutcoupled condensate forup to 1 second
Page 11S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Next Steps: Bragg atom interferometry
0 1 2
|g>Ener
gy
|e>
)( dw +hdh
wh
Dh
khMomentum in
time
)( dw +hwh
§ Currently in ground test phase
Page 12S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
QUANTUS2
§ Adding a second atomic species (potassium)à Demonstrate first Degenerate Fermi Gases in µgà Demonstrate first Bose-Fermi-Mixtures in µgà Test of the weak equivalence principle
§ Increasing the atom number in the BEC to ~105
àbetter signal to noise ratio after longer TOF
§ Capability for high precision atom interferometry
§ Use of the catapult mode of the drop tower in Bremen
Page 13S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The new apparatus QUANTUS2: Overview - Capsules
QU
ANTU
S (d
rop
mod
e)
QU
ANTU
S2 (c
atap
ult
mod
e)
Payload area:ø600x1730 mm à ø600x950 mm
Payload mass:234 kgà163,8 kg
2860
mm
2094
mm
Reduction of size and mass:
Page 14S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The new apparatus QUANTUS2: Vacuum systemCapsule with/without magnetic shields
Vacuum pumpsand electronics
Vacuum chamberMagnetic shield
Laser systems
Used by ZARM
Page 15S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
The new apparatus QUANTUS2: Vacuum systemDouble MOT System:
CCD camera head
telescopes
Experiment chamber 2D-MOT
coils
CF16 valve
~420mm
Page 16S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Micro optical bankAlN 13x4x1mm3
Master-OscillatorDFB-RW-LaserPower Amplifier
Trapered- amplifier
Micro lensGRIN-rod lens
The new apparatus QUANTUS2: Laser systemDevelopment of new technologies:
• e.g. Hybrid MOPA system:
• DFB/DBR laser for 767nm• narrow linewidth DFB/DBR laser diodes• ECDL laser on a micro bank
Housing(2.5x2.5x1mm)
At the HU Berlin/Ferdinant-Braun Institutfür Hochfrequenztechnik (FBH)
Page 17S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
TEXUS
§ Ballistic missile launch§ Quality of microgravity 10-5 (ZARM 10-6)§ 6 minutes of microgravity (ZARM 9s)
Page 18S. T. Seidel Bose-Einstein Condensation in Microgravity Varenna, 30.06.2009
Thank you for your attention
QUANTUS is a collaboration of
Financed by: