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Atom Interferometers and Atomic Clocks: From Ground to Space

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. Laser cooling of atoms. n L. n L. v. Lab ref. frame. Idea:

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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 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 MOTLENS, Firenze

  3. Laser cooling: temperatures Atomic Temperature : kBT = Mv2rms Minimum temperature for Doppler cooling: Single photon recoil temperature: Examples: TD Tr Na 240 mK 2.4 mK Rb 120 mK 360 nK Cs 120 mK 200 nK

  4. The Nobel Prize in Physics 1997

  5. The Nobel Prize in Physics 2001

  6. Atomic beam Oven laser atom laser Atom optics lenses atom laser atom mirrors 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, 090405 (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. Atomic clocks The definition of the second The second is the duration of 9 192 631 770 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

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

  16. 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)…

  17. 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, 243002 (2003)

  18. 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

  19. Atom Interferometers

  20. Quantum interference 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*)

  21. Atomic clocks: Interference fringes

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

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

  24. Matter wave sensors accelerations: rotations:

  25. 30 cm W 50 cm SYRTE cold atom gyroscope One pair of Raman lasers switched on 3 times 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 : 4 10-8 rad.s-1.Hz-1/2 • accelerometer : 3 10-8 m.s-2.Hz-1/2 Magneto-Optical Traps

  26. IQO Cold Atom Sagnac Interferometer 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

  27. g Misura Accurata di G mediante Interferometria Atomica MAGIA • Measure g using free falling atoms and atom interferometry • Add known source masses • Measure change of g Determine G aM 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) http://www.fi.infn.it/sezione/esperimenti/MAGIA/home.html

  28. Misura Accurata di G mediante Interferometria Atomica MAGIA In collaboration with LNF, Frascati http://www.fi.infn.it/sezione/esperimenti/MAGIA/home.html

  29. Source masses and support MAGIA: Firenze atom gravity gradiometer apparatus Laser and optical system Phase locked lasers for Raman transitions L. Cacciapuoti et al., Rev. Scient. Instr. 76, 053111 (2005)

  30. MAGIA: first results

  31. 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

  32. 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 Example: r 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

  33. From Earth Laboratories to Space

  34. µwave-link two-ways Atomic Clock Ensemble in Space H= 400 km V=7 km/s T= 5400 s • 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

  35. ACES ACES ON COLUMBUS EXTERNAL PLATFORM M = 227 kg P = 450 W Launch date : 2009 Mission duration : 18 months

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

  37. ESA-AO-2004 Life and Physical Sciences and Applied Research Projects

  38. PARCSPrimary Atomic Reference Clock in Space

  39. 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 http://sci.esa.int/home/hyper/index.cfm

  40. ESA-AO-2004 AI

  41. Laser Cooled Atom (LCA) Sensor for Ultra-High-Accuracy Gravitational Acceleration and Rotation Measurements in response to ESA ITT No. AO-1-4477/03/NL/CH

  42. Laser system SpacePart ‘03 Prototype field ready sensor W.W. Hansen Experimental Physics Laboratory, Stanford, CA 94305 Sensor head Sensor optomechanics From M. Kasevich talk at SpacePart '03 Conference Washington D.C., December 10th - 12th, 2003.

  43. JPL http://horology.jpl.nasa.gov/quantum/atominterferometry.html

  44. BEC in space

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

  46. 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

  47. Future prospects:Atomic clocks • New optical clocks with fractional stability ~ 10-17-10-19 • 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, …

  48. 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

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