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Atom Interferometers and Atomic Clocks: From Ground to Space

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1 Atom Interferometers and Atomic Clocks: From Ground to Space
Guglielmo M. Tino Università degli Studi di Firenze - Dipartimento di Fisica, LENS Istituto Nazionale di Fisica Nucleare - Sezione di Firenze

2 Laser cooling of atoms nL nL nL(1-v/c) nL(1+v/c) v Lab ref. frame
Idea: T.W. Hänsch, A. Schawlow, 1975 Exp. demonstration: S. Chu et al., 1985 nL(1-v/c) nL(1+v/c) Atom ref. frame Sr MOT LENS, Firenze OK

3 Laser cooling: temperatures
Atomic Temperature : kBT = Mv2rms Minimum temperature for Doppler cooling: Single photon recoil temperature: Examples: TD Tr Na 240 mK mK Rb 120 mK 360 nK Cs 120 mK 200 nK OK

4 The Nobel Prize in Physics 1997

5 The Nobel Prize in Physics 2001

6 Atom optics lenses atom laser mirrors beam-splitters interferometers
Oven laser Atomic beam lenses atom laser atom mirrors laser atom laser beam-splitters interferometers

7 Atom Michelson Interferometer on a Chip Using a Bose-Einstein Condensate
Ying-Ju Wang, Dana Z. Anderson, Victor M. Bright, Eric A. Cornell, Quentin Diot, Tetsuo Kishimoto, Mara Prentiss, R. A. Saravanan, Stephen R. Segal, Saijun Wu, Phys. Rev. Lett. 94, (2005)

8 Atomic clocks

9 The measurement of time
OSCILLATOR COUNTER Accuracy  realization of the standard Stability  stability of the frequency: depends on of the oscillator

10 The definition of the second
Atomic clocks The definition of the second The second is the duration of periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the 133Cs atom (13th CGPM, 1967) Dn.Dt = 1

11 Atomic fountain clock NIST-F1 G.M. Tino, Firenze, 11/12/2003

12 Cold Atoms Clocks in Space
Interrogate fast (hot) atoms over long distances  T = 10 ms Use laser cooled atoms, limitation due to the presence of gravity  T = 1 s Use laser cooled atoms in microgravity  T = 10 s PHARAO C. Salomon et al., C.R. Acad. Sci. 2, 1313 (2001)

13 Accuracy of the atomic time
from C. Salomon

14 Optical clocks: Towards 10-18-10-19
• Narrow optical transitions dno ~ 1 Hz, n0 ~ 1015 Hz • Candidate atoms Trapped ions: Hg+, In+, Sr+, Yb+,… Cold neutral atoms: H, Ca, Sr, Yb,… (Fermions?) • Direct optical-mwave connection by optical frequency comb Th. Udem et al., Nature 416 , 14 march 2002


16 From L. Hollberg, Hyper symposium 2002
Ca clock example From L. Hollberg, Hyper symposium 2002

17 87Sr optical clock Method: (H. Katori)
Interrogate atoms in optical lattice without frequency shift Long interaction time Large atom number (108) Lamb-Dicke regime Excellent frequency stability Small frequency shifts: No collisions (fermion) No recoil effect (confinement below optical wavelength) Small Zeeman shifts (only nuclear magnetic moments)…

18 Towards a Sr clock – The experiment in Firenze
Firenze 2003, Magneto-optical trapping of all Sr isotopes 1S0 - 3P1 (7.5 kHz) 1S0 - 3P0 (1 mHz, 87Sr) 1S0 - 3P2 (0.15 mHz) Optical trapping in Lamb-Dicke regime with negligible change of clock frequency • Optical clocks using visible intercombination lines Comparison with different ultra-stable clocks (PHARAO/ACES) PHARAO G. Ferrari, P.Cancio, R. Drullinger, G. Giusfredi, N. Poli, M. Prevedelli, C. Toninelli and G.M. Tino, Phys. Rev. Lett. 91, (2003)

19 Atomic clocks Location finding
Precision navigation and navigation in outer space Variability of Earth’s rotation rate and other periodic phenomena Earth’s crustal dynamics Secure telecommunications Very Long Baseline Interferometry (VLBI) Spectroscopy Expression of other physical quantities in terms of time Tests of constancy of fundamental constants Tests of the special and general theories of relativity

20 Atom Interferometers

21 Quantum interference Interference of transition amplitudes
path I amplitude AI Initial state |yi Final state |yf path II amplitude AII Interference of transition amplitudes P(|yi|yf) = |AI + AII|2 = |AI|2 + |AII|2 + 2 Re(AI AII*)

22 Atomic clocks: Interference fringes

23 Time-domain Ramsey-Bordé interferences with cold Ca atoms (PTB)

24 Atom Interferometry Atom interferometer Phase difference
atomic flux at exit port 1 at exit port 2 Phase difference

25 Matter wave sensors accelerations: rotations:

26 SYRTE cold atom gyroscope
50 cm 30 cm One pair of Raman lasers switched on 3 times W Detections Launching velocity: 2.4 m.s-1 Maximum interaction time : 90 ms 3 rotation axes 2 acceleration axes Cycling frequency 2Hz Expected sensitivity (106 at): gyroscope : rad.s-1.Hz-1/2 accelerometer : m.s-2.Hz-1/2 Magneto-Optical Traps

27 IQO Cold Atom Sagnac Interferometer
p p/2 Detection Preparation p/2 3 mm 15 cm A MOT 2 MOT 1 C. Jentsch, T. Müller, E. Rasel, and W. Ertmer, Gen. Rel. Grav, 36, 2197 (2004) & Adv. At. Mol. Physics

28 MAGIA Measure g using free falling atoms and atom interferometry
Misura Accurata di G mediante Interferometria Atomica Measure g using free falling atoms and atom interferometry Add known source masses Measure change of g Determine G aM g G.M. Tino, in “2001: A Relativistic Spacetime Odyssey”, World Scientific (2003) M. Fattori, G. Lamporesi, T. Petelski, J. Stuhler, G.M. Tino, Phys. Lett. A 318, 184 (2003)

29 In collaboration with LNF, Frascati
MAGIA Misura Accurata di G mediante Interferometria Atomica In collaboration with LNF, Frascati

30 MAGIA: Firenze atom gravity gradiometer apparatus
Source masses and support Laser and optical system Phase locked lasers for Raman transitions L. Cacciapuoti et al., Rev. Scient. Instr. 76, (2005)

31 MAGIA: first results

32 G. Ferrari et al., 2006, to be published
Precision Measurement of Gravity at Micrometer Scale using Ultracold Sr Atoms n = m g l /2 h G. Ferrari et al., 2006, to be published

33 Test of the gravitational 1/r2 law in the sub-mm range with atom interferometry sensors (Casimir?)
95% confidence level constraints on a Yukawa violation of the gravitational inverse-square law. The vertical axis represents the strength of a deviation relative to that of Newtonian gravity while the horizontal axis designates its characteristic range. The yellow region has been excluded (From S. J. Smullin et al., 2005) a = 2pGrd r Example: rAu 19 g/cm3 d  200 mm a  2 x 10-9 ms-2 -d- n = m g l /2 h G.M. Tino, in “2001: A Relativistic Spacetime Odyssey”, Firenze, 2001, World Scientific (2003) G.M. Tino, Nucl. Phys. B 113, 289 (2002) G. Ferrari et al., 2006, to be published

34 From Earth Laboratories to Space

35 Atomic Clock Ensemble in Space
H= 400 km V=7 km/s T= 5400 s µwave-link two-ways A cold atom clock in space Worldwide access Fundamental physics tests PHARAO : Cold Atom Clock in Space. CNES (France) A. Clairon, P. Laurent, P. Lemonde, M. Abgrall, S. Zhang, C. Mandache, F. Allard, M. Maximovic, F. Pereira, G. Santarelli, Y. Sortais, S. Bize, H. Marion, D. Calonico, (BNM-LPTF), N. Dimarcq (LHA), C. Salomon (ENS) SHM : Space Hydrogen Maser. ON (Switzerland) L. Jornod, D. Goujon, L.G. Bernier, P. Thomann, G. Busca MWL : Microwave link. Kayser-Threde-Timetech (Germany) W. Schaefer, S. Bedrich ACES is open to any interested scientific user W. Knabe, P. Wolf, L. Blanchet, P. Teyssandier, P. Uhrich, A. Spallici New members : 2001: UWA (Australia), A. Luiten, M. Tobar, J. Hartnett, R. Kovacich 2002: LENS (Italy), G.M. Tino, G. Ferrari, L. Cacciapuoti ESA: MSM Stephen Feltham CNES: C. Sirmain + team of 20 engineers at CST, Toulouse Support: ESA, CNES, BNM, CNRS

M = 227 kg P = 450 W Launch date : 2009 Mission duration : 18 months

37 ACES objectives L. Blanchet, C. Salomon, P. Teyssandier, and P. Wolf, A&A 370, 320 (2001)

38 Life and Physical Sciences and Applied Research Projects
ESA-AO-2004 Life and Physical Sciences and Applied Research Projects

39 PARCS Primary Atomic Reference Clock in Space

40 HYPER Mapping Lense-Thirring effect close to the Earth
Improving knowledge of fine-structure constant Testing EP with microscopic bodies Differential measurement between two atom gyroscopes and a star tracker orbiting around the Earth Atomic gyroscope control of a satellite

41 ESA-AO-2004 AI

42 Laser Cooled Atom (LCA) Sensor
for Ultra-High-Accuracy Gravitational Acceleration and Rotation Measurements in response to ESA ITT No. AO /03/NL/CH

43 Prototype field ready sensor
SpacePart ‘03 W.W. Hansen Experimental Physics Laboratory, Stanford, CA Sensor head Sensor optomechanics Laser system From M. Kasevich talk at SpacePart '03 Conference Washington D.C., December 10th - 12th, 2003.

44 JPL

45 BEC in space

46 From E. Rasel, 2005 DC-DC transformer Computer control Laser pumps
µ-metal shielding Battery pack From E. Rasel, 2005


48 Applications of new quantum sensors based on atom interferometry
G • Measurement of fundamental constants a • New definition of kg • Test of equivalence principle • Short-distances forces measurement • Search for electron-proton charge inequality • New detectors for gravitational waves ? geophysics • Development of transportable atom interferometers space

49 Future prospects: Atomic clocks
• New optical clocks with fractional stability ~ • mm-scale positioning and long-distance clock syncronization • Very large baseline interferometry (VLBI) and geodesy • Search for variation of fundamental constants • Tests of SR and GR in Earth orbit (ACES, OPTIS) • Improved tests of GR in solar orbit: Shapiro delay, red shift, …

50 Conclusions New atomic quantum devices can be developped with unprecedented sensitivity using ultracold atoms and atom optics Applications: Fundamental physics, Earth science, Space research, Commercial Well developped laboratory prototypes Work in progress for transportable/space-compatible systems

51 Fine


53 h/m and fine structure constant
S. Chu et al., 2002

54 Unit of mass The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram (1st CGPM, 1889) Goal: Redefinition of kg on microscopic quantities with accuracy better than 10-8 Idea: Watt-balance compares electrical and mechanical realization of Watt Watt balance groups working at NPL (UK), NIST (USA), METAS (Switzerland), BNM (France) Force of coil in magnetic flux gradient

55 Tests of weak equivalence principle
Best tests so far: EOT-Wash group (Adelberger, Gundlach), See “” Long range EP tested at the level of 10-13 Prospects Space: MICROSCOPE  10-15 STEP  10-18 ( ) Atoms: • different isotopes, e.g. 85Rb vs 87Rb • different atoms, e.g. Rb vs Cs • bosons vs fermions, e.g. Rb vs 40K • different spins • anti-matter (?) Fray S, et al. PRL. 93, (2004) Dg/g=(0.4+/-1.2)x10-7

56 Test of equivalence principle for anti-matter
243 nm 121.6 nm 1/2 3/2 1420 MHz 1 177 MHz 3s1/2 3p 4 5 H levels partial scheme (not to scale) 10968 MHz 59 MHz 24 MHz • Compare g H H • Steps:  anti-H production (ATHENA, ATRAP)  anti-H selective state population  anti-H cooling  anti-H trapping  g measurement: Dg/g  10-3 ? - Time of flight - Atom interferometry Raman transitions between 2S HFS sublevels 2Shigh-P levels transitions (T. Heupel et al., Europhys. Lett. 57, 158 (2002)) Dg/g  10-9 ?

57 Search for electron-proton charge inequality
Electrostatic, ferromagnetic, diamagnetic levitation Millikan (1935), Morpurgo ( ), Braginsky (1970), Stover (1967), Rank (1968), LaRue (1979) Gas flow Piccard and Kessler (1925), Hillas & Cranshaw (1960), King (1960) Acoustic cavity Dylla and King (1973) Atomic and molecolar beams Hughes (1957), Chamberlain & Hughes (1963), Fraser (1965), Shapiro (1957), Shull (1967) Present limit dep< 1x10-21 e (From G. Carugno and G. Ruoso)

58 (Da G. Carugno and G. Ruoso)
Neutralità materia dep = qe+ qp; qn ; qn Motivazioni: digressione storica Limiti su qn e qn Se C e CPT conservati da qn = qe + qp + qn ricavo limiti Attualmente qn < e Esp. con fasci di neutroni termici (1988) qn < e Da astrofisica, Barbiellini - Cocconi (1987) Einstein (1929) Spiegare campi magnetici terra e sole dep + rotazione -> i -> B si aspettava dep= 3x10-19 e Bondi - Lyttleton (1959); Hoyle (1960) se dep~ 2x10-18 e => espansione universo Feinberg - Goldhaber (1959); Gell-Mann - Nambu (1960) dep ≠ 0 per spiegare leggi di conservazione (es. numero barionico) Chiu - Hoffmann (1964) Indipendenza della carica dell’elettrone dalla velocità e trasformazioni di Lorentz Con atomi di vario Z miglioro limite (Da G. Carugno and G. Ruoso)

59 Search for electron-proton charge inequality
dep< 1x10-25 e ?

60 Gravitational wave detection by atom interferometry
Virgo Presentation at 2004 Aspen Winter College on Gravitational Waves: See See also: Chiao RY, Speliotopoulos AD, J. Mod. Opt. 51, 861 (2004) A. Roura, D.R. Brill, B.L. Hu, C.W. Misner, gr-qc/

61 Sources - Detectors h [1/sqrt Hz] f [Hz] -18 -20 -22 -24 SN core
collapse 1 LISA 2 LIGO – Virgo 3 A.I. -18 1 Coalescence of massive BH 2 3 -20 ms Pulsars (1 y) -22 Slow Pulsars (1 y) LMXRBs & Perturbed “newborn”NS Galactic binaries NS-NS and BH-BH Coalescence -24 f [Hz]

62 Gravimeters A. Peters, K.Y. Chung and S. Chu, Nature 400, 849 (1999)
Resolution: 3x10-9 g after 1 minute Absolute accuracy: g/g<3x10-9

63 Gravimeter application in geophysics
Gravimetric measurements at Etna Pizzi DeNeri site during a 48-h-long period encompassing the beginning of the eruption (Branca et al. Geoph. Res. Lett (2003))

64 Gravimeter Application
Geophysical research Monitoring of magma migration in active volcanic areas Detection of vertical crustal motion in seismogenic areas Post glacial rebound studies Measuring uplift in subduction areas Earthquake (strain accumulation in tectonic areas during interseismic phase) Calibrating measurement made by other techniques: height measurements, relative gravimeter Environmental monitoring Water table monitoring in deep and/or multiple acquifers Monitoring of mining effect Slope and earth fill dam stability Global sea level studies for earth warming assessment On site inspection of sites for nuclear test or else. Mineral exploration

65 Gradiometer applications
Airborne gravity measurement for oil and mineral exploration hazard investigation Satellite gravity meausrement : GOCE project GRACE Project Gravity gradiometry gives higher resolution in Monitoring of anomalies Data processing Joint gravimetric-seismological data inversion Gradiometer based on absolute Gravimeter combines complementary range of sensitivity for different mass/distance source Tensorometer

66 ACES: Relativity tests

67 Search for variation of a

68 Search for variation of a

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