Atomic Quantum Sensors and Fundamental Tests

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1 Atomic Quantum Sensors and Fundamental Tests C. Salomon Laboratoire Kastler Brossel, Ecole Normale Supérieure, Paris Pre Doc school Les Houches, September 16th, 2014

2 1989: N. Ramsey, W. Paul, H. Dehmelt Separated oscillatory fields method for atomic clocks, ion trap techniques S. Chu, C. Cohen-Tannoudji, W. Phillips 1997: Laser manipulation of atoms 2005: J. Hall, T. Haensch, R. Glauber Laser precision spectroscopy Optical frequency comb Quantum optics 2012: S. Haroche, D. Wineland Control of individual quantum objects Photons and atoms

A new frontier: connecting precision measurements and

Wieman 2001: Bose-Einstein Condensation Atom-Atom

Cesium fountain clocks, Rubidium is much better!

3 A new frontier: connecting precision measurements and many-body physics E. Cornell W. Ketterle C. Wieman 2001: Bose-Einstein Condensation Atom-Atom interactions are a limit to sensor precision, Example: Cesium fountain clocks, Rubidium is much better! But : Spin squeezing, interferometry below standard quantum limit Continuous atom lasers

4 Fundamental Questions 1) Missing mass in the Universe Dark matter and dark energy represent 95% of the mass of the Universe but have unknown origin! New particles and/or change of the laws of gravity? 2) Atomic quantum sensors can tests fundamental laws with exquisite precision Einstein s equivalence principle and Universality of Free Fall Measurement of the gravitational constant G Proposal for detection of gravitational waves Precision redshift measurement Variability of fundamental constants 3) Quantum sensors have societal applications Accelerometry, Gravimetry, Navigation, GPS, GALILEO, GLONASS, Geodesy, Earth monitoring,

5 Atomic Quantum Sensors 1) Use quantum interference in atoms for precision measurements Matter-wave interferometers and clocks as old as Quantum Mech. 2) Cold atoms: New opportunities with large De Broglie wavelength Atomic Source λ = h / Beam splitter Mv 3 ) Space: long interrog. time, microgravity, quietness, world coverage DETECTOR Atom interferometry and clocks Beam recombiner Atomic source Beam splitters: lasers, photon recoil Detectors

6 Atom interferometers and Clocks Atoms have internal states Two level atom: g, e Laser resonant on g e transition Neglect spontaneous emission Use long lived upper states Mg, Ca, Sr, Yb, or Raman Transition between hyperfine ground states in alkalis for instance Effective two-level system e +k 1 -k 2 g 2 g 1 Bloch oscillations in a gravitational field

to T L Inertial sensors: Accelerometers: gain as T 2 Sagnac gyrometers : gain as L T Current sensitivity:

7 Matter-wave sensors and precision measurements Clocks and Interferometers T : interaction time with ELM field Slow atoms: T large; atomic fountain or microgravity Trapped atoms: T large Clocks: gain prop. to T L Inertial sensors: Accelerometers: gain as T 2 Sagnac gyrometers : gain as L T Current sensitivity: Acceleration: δg/g= in 1s Rotation: Ω= rad s -1 in 1 s Clocks: Frequency stability: δν/v = in 1s Accuracy: =

8 Optical clocks Mach-Zehnder interferometer with light beams π 2 π π 2 e, p+ k Atom beam g, p g, p t 0 t 1 t 2 Laser beams Time δφ = φ ( t ) 2 φ ( t ) + φ ( t ) Sensitive to rotation and accelerations: gyrometers and gravimeters

Cold atom gravimeter S. Chu, Kasevich et al., Stanford δφ = k at = k gt = 2k gt 2 2 2 eff eff L Ground sensitivity: σ g ~10-7 m.

9 Cold atom gravimeter S. Chu, Kasevich et al., Stanford δφ = k at = k gt = 2k gt eff eff L Ground sensitivity: σ g ~10-7 m.s -2 at 1s with interrogation time 100 ms limited by vibrations Extrapolation to space: <10-10 m.s -2 at 1s with interrogation time 2 s With ultra-cold atoms: ~10-11 m.s -2 at 1s with interrogation time 10 s 3D MOT 2D MOT 1 m A. Landragin F. Pereira, SYRTE Earthquake in China 2 Mars 20 th 2008 (magnitude 7,7) muquans company

10 Measurement of G by atom interferometry Tino s group LENS Nature 2014 Two atomic clouds: gradiometer geometry Movable tungstene mass One week of measurements

11 Measurement of G by atom interferometry (2) Uncertainty: 150 ppm 1.5 σ below Codata value

12 Space-Time Sensors 2 Atomic Clocks

Time measurement Find a periodic phenomenon: 1) Nature: observation: Earth rotation, moon rotation, orbit of pulsars,.. 2) Human realization: egyptian sandstone, Galileo pendulum.

13 Time measurement Find a periodic phenomenon: 1) Nature: observation: Earth rotation, moon rotation, orbit of pulsars,.. 2) Human realization: egyptian sandstone, Galileo pendulum. simple phenomenon described by a small number of parameters The faster the pendulum, The better is time resolution T = 2 π l/ g 3) Modern clocks use electromagnetic signals locked to atomic lines

and of width ν A servo system forces ν to stay equal to the atomic Oscillator frequency ν A An atomic clock is an

14 Atomic Clock An oscillator of frequency ν produces an electromagnetic wave which excites a transition a - b The transition probability a b as a function of ν has the shape Atomic transition of a resonance curve centred in ν A = (E b -E a ) / h and of width ν A servo system forces ν to stay equal to the atomic Oscillator frequency ν A An atomic clock is an oscillator whose frequency is locked to that of an atomic transition The smaller ν, the better is the precision of the locked system ν Α ν

15 Precision of Time 1s 1ms 1µs 1ns 1ps Less than 1second error over the age of the universe! Fountains GPS Time 100 ps/day 10 ps/day 0.1 ps/day Optical clocks

16 Ramsey resonance in an atomic fountain S/N= 5000 per point S. Bize et al, J Phys B 05

17 Comparison between two Fountains FOM and FO2 (Paris Observatory) S. Bize et al. EFTF 08 J. Phys. B 2005 SYRTE Frequency stability below after 5 to10 days of averaging Accuracy: agreement between the Cesium frequencies:

Atomic Fountains and TAI 15 fountains in

~10 report to BIPM with accuracy of a few 1

18 Atomic Fountains and TAI 15 fountains in operation at SYRTE, PTB, NIST, USNO, Penn St, INRIM, NPL, Neuchatel, JPL, NIM, NMIJ, NICT, Sao Carlos,. ~10 report to BIPM with accuracy of a few Realize the International Atomic Time, TAI LNE-SYRTE, FR PTB, D NIST, USA

19 171 Yb Optical Lattice Clocks at s N. Hinkley,J. A. Sherman, N. B. Phillips, M. Schioppo, N. D. Lemke, K. Beloy, M. Pizzocaro, C. W. Oates, A. D. Ludlow, Science 13

20 1997 The space clock mission ACES

21 A cold atom Cesium clock in space Fundamental physics tests Worldwide access To be launched to ISS May 2016, by Space X Dragon capsule ACES atomic clocks

22 ACES General View Earth Mass: 227 kg, Power 450 W Challenges: thermo-mechanical stability, three year operation

23 ACES ON COLUMBUS EXTERNAL PLATFORM ACES Current launch date : May 2016 Mission duration : 18 months to 3 years

24 Current Network of Ground Institutes JPL NIST SYRTE PTB NPL NICT + 1 transportable MWL GT for other European institutes UWA + 1 transportable MWL GT for calibration/troubleshooting purposes METAS, INRIM, Delivery of first two MWL GT units is planned at end of 2014

Do fundamental physical constants vary with time?

different nature as a function of time Microwave

25 Do fundamental physical constants vary with time? Motivation: unification theories, string theory, Damour, Polyakov, Marciano,. α elm, m e / m p Principle : Compare two or several clocks of different nature as a function of time Microwave clock/microwave clock: α, m e /m p, g (i) rubidium and cesium Microwave/Optical clock : α, m e /m p, g (i) Optical Clock / Optical clock: α

26 SYRTE Comparison between Rubidium and Cesium Hyperfine Structure over ~15 years Weighted least square fit to a line d dt ν ln( ν Rb Cs ) ( 1.36 ± 0.91) = yr The yearly drift deviates from zero by 1.5 standard deviation: not statistically significant. The uncertainty improves by a factor of 7.7 over last report [PRL 90, (2003). J. Guéna et al., Phys. Rev.Lett.109 (2012) With QED calculations: J. Prestage, et al., PRL (1995), V. Dzuba, et al., PRA (1999) d g Rb ln( α ) = ( 1.36 ± 0.91) 10 yr dt g Cs With QCD calculations: T.H. Dinh et al., PRA79 (2009) NIST 08 T. Rosenband et al., Science Express, 2008 d dt Al + -Hg + optical ln( α ( frequency m / Λ ) comparison ) = ( 1.36 ± 0.91) over 1018 q QCD yr months: dα/αdt= ( )x /year

27 ACES Global search for variations of fundamental constants by long distance clock comparisons at /year Cs, Rb, Ca, Yb +, Sr Cs, Rb, Sr, Hg H, In+, Mg, Ag Cs, Yb +, Yb +, Cs,Hg + Al +, Sr, Ca, Yb Cs,Rb Cs, Rb, Sr +, Yb +

Gravitational redshift with ACES U 2 U 1 ν U U = 1+ ν 2 2 1 2 1 c

28 Gravitational redshift with ACES U 2 U 1 ν U U = 1+ ν c Redshift : With clock ACES: ~ Factor 70 gain over GP-A 1976

29 Cold Atom Clock in µ-gravity : PHARAO/ACES kg, 36W Total volume: 990x336x444 mm3 Mass: 44 kg

30 PHARAO clock

PHARAO Space Clock 1,0 Probabilité 0,8 0,6 0,4 0,2 Laser source 0,0-300 -200-100 0 100 200 300 Cesium tube Frequency

31 PHARAO Space Clock 1,0 Probabilité 0,8 0,6 0,4 0,2 Laser source 0, Cesium tube Frequency Fréquence (Hz) Flight model tests completed in Toulouse Ready for launch! expected accuracy and stability: in space

32 PHARAO Cesium Tube on the Shaker

33 PHARAO Team in Toulouse

to TAI Gain: x 20 wrt current GPS Common view non common view Error

34 ACES TIME Transfer Ultra-stable frequency comparisons on a worldwide basis : Ground Clock comparisons@ over one week Contribution to TAI Gain: x 20 wrt current GPS Common view non common view Error < 0.3ps over 300 s Can be checked by fiber-link Error < 3ps over 3000 s

35 ACES Time Transfer The microwave link ground terminal 100 fs Time stability of carrier with 10 Kelvin peak to peak temperature variation PTB, SYRTE, NPL, JPL, NIST, Tokyo, UWA, METAS, MWL End to End tests are ongoing

Relativistic Geodesy The clock frequency depends on the Earth gravitational potential 10-16 per meter

(NIST, JILA) Competitive With ACES: with satellite + levelling techniques at ~ 20 cm level

36 Relativistic Geodesy The clock frequency depends on the Earth gravitational potential per meter Best ground clocks have accuracy of and will improve! (NIST, JILA) Competitive With ACES: with satellite + levelling techniques at ~ 20 cm level Possibility to measure the potential difference between the two clock locations at level ie 10 cm and ie 1cm ACES with fiber link. Geoid H

37 Future Time Definition from Space 1) The Earth gravitational potential fluctuations will limit the precision of time on the ground at (ie: cm to mm level) 2) The only solution: set the reference clocks in space where potential fluctuations are vastly reduced 3) Improved Navigation, Earth Monitoring and Geodesy Towards a space-time reference frame in Earth orbit

38 Summary Matter-wave interferometers and cold atom clocks have entered into high precision measurement phase Lectures of G. Tino and P. Cladé Technology has progressed fast with routinely working instruments Atomic clocks reach stabilities and accuracies in the range Impressive efforts for miniaturization and reliability for space and ground Compact laser sources and atom chips quantum gases sources: BEC in microgravity and atom lasers ACES on the ISS ( ): tests of relativity Optical Clocks with frequency stability in 2020 on the ISS or satellite Test of Equivalence Principle in Space with quantum objects beyond Current ESA Call M4 mission High precision quantum sensors will bring tests of the laws of gravitation to a new level of precision

Thanks! L. Duchayne, X. Baillard, D. Magalhaes,C. Mandache, P. G. Westergaard, A.

Lemonde, P. Laurent, M. Lours, G. Santarelli, P. Rosenbusch, D. Rovera, M.

Meynadier, A. Clairon, M. Tobar, J. Hartnett, A. Luiten, J. Mc Ferran, C. Vale F.

Schreiber, W. Bosch, A. Schlicht G. Tino, P. Thomann, S. Schiller, L. Cacciapuoti, R.

Katori, M. Fujieda, Y. Hanado, S. Watabe, Nan Yu, R. Toelkjer, K. Gibble L.

39 Thanks! L. Duchayne, X. Baillard, D. Magalhaes,C. Mandache, P. G. Westergaard, A. Lecallier, F. Chapelet, M. Petersen, J. Millo, S. Dawkins, R.Chicireanu, S. Bize, P. Lemonde, P. Laurent, M. Lours, G. Santarelli, P. Rosenbusch, D. Rovera, M. Abgrall, R. Le Targat, Y. Lecoq, P. Delva, P. Wolf, J. Guéna, J. Lodewyk, F. Meynadier, A. Clairon, M. Tobar, J. Hartnett, A. Luiten, J. Mc Ferran, C. Vale F. Riehle, E. Peik, D. Piester, A. Bauch O. Montenbruck, G. Beyerle, Y. Prochazka, U. Schreiber, W. Bosch, A. Schlicht G. Tino, P. Thomann, S. Schiller, L. Cacciapuoti, R. Nasca, S. Feltham, R. Much, O. Minster, S. Jefferts, J. Ye, D. Wineland, H. Katori, M. Fujieda, Y. Hanado, S. Watabe, Nan Yu, R. Toelkjer, K. Gibble L. Hollberg, S. Léon, D. Massonnet and 15 engineers at CNES L. Blanchet, C. Bordé, C. Cohen -Tannoudji, C. Guerlin, S. Reynaud

The ACES/PHARAO Space Mission Fundamental Physics Tests with Space Clocks

The ACES/PHARAO Space Mission Fundamental Physics Tests with Space Clocks Peter Wolf and C. Salomon LNE-SYRTE and Laboratoire Kastler Brossel, Paris Workshop «Atomes Froids et Applications Embarquées»