Transcript of Jason Hogan May 22, 2014 LISA Symposium X Single-arm gravitational wave detectors based on atom...
- Slide 1
- Jason Hogan May 22, 2014 LISA Symposium X Single-arm
gravitational wave detectors based on atom interferometry
- Slide 2
- Are multiple baselines required? L (1 + h sin(t )) strain
frequency Single Baseline Gravitational Wave Detection Motivation
Formation flying: 2 vs. 3 spacecraft Reduce complexity, potentially
cost Laser interferometer GW detector
- Slide 3
- Atom interference Light interferometer Atom interferometer Atom
http://scienceblogs.com/principles/2013/10/22/quantum-erasure/
http://www.cobolt.se/interferometry.html Light fringes Beamsplitter
Mirror Atom fringes
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- Measurement Concept Essential Features 1.Atoms are good clocks
2.Light propagates across the baseline at a constant speed Atom
Clock Atom Clock L (1 + h sin(t ))
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- Simple Example: Two Atomic Clocks Time Phase evolved by atom
after time T
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- Simple Example: Two Atomic Clocks Time GW changes light travel
time Phase difference
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- Phase Noise from the Laser The phase of the laser is imprinted
onto the atom. Laser phase noise, mechanical platform noise, etc.
Laser phase is common to both atoms rejected in a differential
measurement.
- Slide 8
- Single Photon Accelerometer Three pulse accelerometer
Long-lived single photon transition (e.g. clock transition in Sr,
Yb, Ca, Hg, etc.) Graham, et al., PRD 78, 042003, (2008). Yu, et
al., GRG 43, 1943, (2011).
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- Two-photon vs. single photon configurations 2 photon
transitions 1 photon transitions Rb Sr How to incorporate LMT
enhancement? Graham, et al., PRD 78, 042003, (2008). Yu, et al.,
GRG 43, 1943, (2011).
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- Laser frequency noise insensitive detector Graham, et al.,
arXiv:1206.0818, PRL (2013) Laser noise is common Excited state
Pulses from alternating sides allow for sensitivity enhancement
(LMT atom optics)
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- LMT enhancement with single photon transition Graham, et al.,
arXiv:1206.0818, PRL (2013) Example LMT beamsplitter (N = 3) Each
pair of pulses measures the light travel time across the baseline.
Excited state
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- Reduced Noise Sensitivity Differential phase shifts (kinematic
noise) suppressed by v/c < 310 -11 1. Platform acceleration
noise a 2. Pulse timing jitter T 3. Finite duration of laser pulses
4. Laser frequency jitter k Leading order kinematic noise
sources:
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- Satellite GW Antenna Common interferometer laser L ~ 100 - 1000
km Atoms JMAPS bus/ESPA deployed
- Slide 14
- Potential Strain Sensitivity J. Hogan, et al., GRG 43, 7
(2011).
- Slide 15
- Technology development for GW detectors 1)Laser frequency noise
mitigation strategies 2)Large wavepacket separation (meter scale)
3)Ultra-cold atom temperatures (picokelvin) 4)Very long time
interferometry (> 10 seconds)
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- Ground-based GW technology development 4 cm Long duration Large
wavepacket separation
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- 10 m Drop Tower Apparatus
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- Interference at long interrogation time 2T = 2.3 sec Near full
contrast 6.710 -12 g/shot (inferred) Interference (3 nK cloud)
Wavepacket separation at apex (this data 50 nK) Dickerson, et al.,
PRL 111, 083001 (2013). Demonstrated statistical resolution: ~5 10
-13 g in 1 hr ( 87 Rb)
- Slide 19
- Preliminary LMT in 10 m apparatus 7 cm wavepacket separation 10
k 4 cm wavepacket separation 6 k LMT using sequential Raman
transitions with long interrogation time. LMT demonstration at 2T =
2.3 s (unpublished)
- Slide 20
- Atom Lens position time Geometric Optics: Atom Lens:
- Slide 21
- Atom Lens Cooling Optical Collimation: Atom Cooling: position
time
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- Radial Lens Beam point source AC Stark Lens Apply transient
optical potential (Lens beam) to collimate atom cloud in 2D
Time
- Slide 23
- 2D Atom Refocusing Without Lens With Lens Lens
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- Record Low Temperature North West Vary Focal Length
- Slide 25
- Extended free-fall on Earth Lens Launch Lens Relaunch Detect
Launched to 9.375 meters Relaunched to 6 meters Image of cloud
after 5 seconds total free-fall time Towards T > 10 s
interferometry (?)
- Slide 26
- Future GW work Single photon AI gradiometer proof of concept
Ground based detector prototype work MIGA; ~1 km baseline (Bouyer,
France) 10 m tower studies
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- 27 AOSense 408-735-9500 AOSense.com Sunnyvale, CA 6 liter
physics package As built view with front panel removed in order to
view interior. Sr compact optical clock
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- Collaborators NASA GSFC Babak Saif Bernard D. Seery Lee
Feinberg Ritva Keski-Kuha Stanford Mark Kasevich (PI) Susannah
Dickerson Alex Sugarbaker Tim Kovachy Christine Donnelly Chris
Overstreet Theory: Peter Graham Savas Dimopoulos Surjeet Rajendran
Former members: David Johnson Sheng-wey Chiow Visitors: Philippe
Bouyer (CNRS) Jan Rudolph (Hannover) AOSense Brent Young (CEO)