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Atom Quantum Sensors on ground and in space
Ernst M. RaselAG Wolfgang Ertmer – Quantum Sensors Division
Institut für QuantenoptikLeibniz Universität Hannover
IQ -
Qua
ntum
Sen
sors
Quantum Matter
InertialQuantum Probes
OpticalClocks
IQ -
Qua
ntum
Sen
sors
Quantum Matter
InertialQuantum Probes
OpticalClocks
free falling proof masses
… guiding the satellite
(laboratory system)
Read out of
distance or relative motion by
optical means,
capacitive measurements, or
magnetometersIner
tial s
ensi
ng
Using atoms as microscopicperfect test masses
Iner
tial s
ensi
ng
Using atoms as microscopicperfect test masses
Quantum Test
Absolute Measurement of inertial forces at low frequency
Ideal identical test bodies: atoms
No charging, no aging effect
Sensitivty increases with T2
Col
d 87
Rb Sagnac Interferometer
Interferometer
MOT 1
π/2
ππ/2
15 cm3 mm
A
PreparationDetection
MOT 2
C. Jentsch, T. Müller, E. Rasel, and W. Ertmer, Gen. Rel. Grav, 36, 2197 (2004)& Adv. At. Mol. Physics
sensitive to both types of inertial forces, rotations and accelerations
transportable
3D-MOTmoving molasses
2D-MOTatomic source 2 detection
interferometer
preparation
Source 1Source 2
Col
d A
tom
Sag
nac
Inte
rfero
met
er
Dua
l int
erfe
rom
etry
time
Detuning of the Raman lasers [Hz]
Exc
itatio
npr
obab
ility
Exc
itatio
npr
obab
ility
Exc
itatio
npr
obab
ility
Exc
itatio
npr
obab
ility
Exc
itatio
npr
obab
ility
C1 = 24% C2 = 22%T = 1ms, τ = 7,5µs
π/2π
π/2
Gyr
osco
pe
⋅=∆ Am2 Atomrot
r
hϕ Ω
r
Rotational Sensitivity with 10 8 ats:
Ground 10-9 rad/√Hz @ Expansion Time 0.025 s
Space 8⋅10-12 rad/√Hz @ Expansion Time 3 s
Earth rotation rate:7.2 10-5 rad/s
Acc
eler
omet
er ⋅=∆ kTacc
r2ϕ ar
Accelerational Sensitivity with10 8 ats:
Ground 10-10 g/√Hz @ Expansion Time 0.2 s
Space 10-12 g/√Hz @ Expansion Time 3 s
IQ -
Qua
ntum
Sen
sors
Quantum Matter
InertialQuantum Probes
OpticalClocks
Clo
ck T
echn
ique
s
OscillatorAtomic
Reference
Feedback
Interrogation
Clock work
Narrow Transitions1mHz - 100 Hz
@ 1010-1015Hz
Atom-optical Techniques & Lasers
forCooling & Trapping,
Preparation, Detection
Frequency-stable, compact, reliable
LasersMonolithic solid state &
Fibre lasers
Cavities and Optics
Mechanical Design, Miniaturisation &
Fibres
Clo
ck T
echn
ique
s
OscillatorAtomic
Reference
Feedback
Interrogation
Clock work
Narrow Transitions1mHz - 100 Hz
@ 1010-1015Hz
Atom-optical Techniques & Lasers
forCooling & Trapping,
Preparation, Detection
Frequency-stable, compact, reliable
LasersMonolithic solid state &
Fibre lasers
Cavities and Optics
Mechanical Design, Miniaturisation &
Fibres
Why
Mg
?Narrow to ultra-narrow transition
"Magic" wave length dipole trap (1S0→3P0: 465 nm)
Higher order effects ?
Reasonable abundance of fermionic and bosonicisotopes 24,25,26Mg
Low black-body shift (10-16)
Simple electronic structure- easy to model
Semi-conductor laser + Frequency Doubling
Clock laser: dye laser (200 Hz) → diode laser
Fast and efficient laser cooling
Mg-
optic
alcl
ock-
an u
p da
te Cooling schemes beyond the Doppler limit
2-photon cooling (500 µK 1D, theore. limit 50 µK)
Sisyphus-cooling of the metastable state
First frequency measurement in Mg 1S0→3P1 with a fibre comb generator and a transportable clock of PTB: preliminary value
655.660.083.836 kHz (acc < 10-11)
New set-up delivering more than 109 trapped atoms (loading of about 4*108 at/s)
1stM
g-fre
quen
cy
mea
sure
men
t 655.660.083.836 kHz +/- 3 kHz
Uncertainty ≤ 10-11
Stability: thermal beam 9*10-13 [1s]
cold atoms 8*10-14 [1s] -200000-20000
-10000
0
10000
Ram
sey-
Bor
dé-S
igna
l [a.
u.]
frequency [Hz]
σ(τ=1s)=8,9*10-13
0 1 2 3 4 5 6 7 8 93836
3837
3838
3839 tue.
ν (c
lock
lase
r)-6
55,6
6008
TH
z [k
Hz]
measurement no.
thu.
Err
or B
udge
t
Effect Shift (Hz) Uncertainty (Hz) Rel. Uncertainty(x10-12)
1st order Doppler 0 554
500
150
5
0.1
0.1
761,2
0,845
2nd order Doppler -1643 0,763
2nd order Zeeman 0.84 0,229
Black body radiation -0.19 0,00763
DC Stark shift 0.1 0,00015
Sagnac effect 1.2 0,00015
Total -1641,1 1,161
IQ -
Qua
ntum
Sen
sors
Quantum Matter
InertialQuantum Probes
OpticalClocks
Dropping BEC
Impl
emen
tatio
nFree Fall: up to 9 sec
Duration > 1 BEC-Experiment
3 flights per day
Test of a robust BEC FacilitiesDimensions < 0.6 ∅ x 1.5 m< 234 kg
Height 110 m
QU
AN
TUS
pumps
µ-metal shielding
Battery pack
Laser
DC-DC transformer
Computer control
The QUANTUS Team, Bose-Einstein condensates in microgravity, AppliedPhysics B: Lasers and Optics, http://dx.doi.org/10.1007/s00340-006-2359-y
286 cm
ATK
AT
4 successfull drops of a magneto-optical trap
Generating BEC
• External MOT
• Chip-MOT
• Moving MOT
• Molasses
• Opt. Pumping
• IP-Trap /Dimple trap
• Evaporation
Incr
easi
ngph
ase
spac
eD
ensi
ty
IQ -
Qua
ntum
Sen
sors
Quantum Matter
InertialQuantum Probes
OpticalClocks
Applications
Adv
anta
ges
of µ
-gra
vity
Extended Time of EvolutionSensitivity ~T2
Perturbation-free EvolutionIdeal inertial reference system
No need to compensate gravity /to levitate the atoms
Comparison of different species
EXTENDED PARAMETER RANGE
• Inertial standards/references
• Earth Observation
• Measurement of relativistic effects & gravity
• Pioneer anomaly
• Testing the Weak Equivalence Principle
• Drag-free sensorsperhaps in gravitational wave detectors ?
Fields of Interest:
Ato
mic
Qua
ntum
Sen
sors
Per
spec
tives
Dual Atomic Accelerometer
2 atomic species of 108 atoms < 1µK
combined with a drag free proof mass(Pathfinder or ONERA type / optical read out)
HYPER orbitAccelerational Sensitivity with 10 8 ats:
Space 10-12 g/√Hz @ Expansion Time 3 s
Pat
hfin
der
Nee
dfo
rFem
to-g
With cold atoms ?
Scaling factor
averaging
Averaging √T/τ
Atomic Temperature an issue and beam splitter velocity : T2
The
BE
C-µ
g Te
am
DLR 50 WM 0346
Drop Tower & SpaceIntegration
Robust & Compact Laser
Atomic Quantum Sensors
Atom-Chip
Theory
Techn. support
Kai BongsWiebke BrinkmannHansjörg DittusWolfgang ErtmerTheodor HänschThorben KönemannClaus LämmerzahlWojciech LewozkoRonald MairoseGerrit NandiAchim PetersPeter PrengelErnst M. RaselJakob ReichelWolfgang SchleichMalte SchmidtTilo SchuldtKlaus SengstockThilo SteinmetzChristian StenzelAnika VogelReinhold WalserTim van Zoest
Thank youfor your attention !
ENOUGH SPACE FOR EXCITING EXPERIMENTS
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