Searching for variations of fundamental constants using the atomic clocks ensemble at LNE-SYRTE

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1 Systèmes de référence Temps-Espace Searching for variations of fundamental constants using the atomic clocks ensemble at LNE-SYRTE Luigi De Sarlo, M Favier, R Tyumenev, R Le Targat, J Lodewyck, P Wolf, J Guéna, S Bize PSAS 2016 Jerusalem, Israel

invariance: coupling constants independent on (space-)time EEP!

2 Einstein s equivalence principle Universality of free fall: cannonball and feather fall the same way as do Rb and Cs atoms Local position invariance: coupling constants independent on (space-)time EEP! α Local Lorentz invariance: constants independent on gravitational potential α α

3 Can we test this in the lab? Violation of local position invariance: coupling constants depend on (space-)time Violation of local Lorentz invariance: coupling constants depend on gravitational potential R XY = X Y = f(,m p /m e,m q / 3 ) so do atomic frequencies ratios!

4 Can we test this in the lab? Violation of local position invariance: coupling constants depend on (space-)time Violation of local Lorentz invariance: coupling constants depend on gravitational potential R XY = X Y = f(,m p /m e,m q / 3 ) so do atomic frequencies ratios! Two examples: d ln R Rb/Cs = 0.49 d ln 0.021d ln(m q / 3 ) d ln R Hg/Sr =0.81d ln T.H. Dinh, et al., PRA (2009) E. J. Angstmann, et al., PRA (2004)

5 Comparisons are the key Local oscillator Useful signal: to be compared! Correction Atomic reference t Rabi = 100 ms ω clock E b E a Interrogation Two families of frequency comparisons: local, distant.

6 The clock ensemble at SYRTE GNSS GNSS Telecom GPS LAB 1 LAB 2

7 The clock ensemble at SYRTE GNSS GNSS Telecom GPS LAB 1 LAB 2 Cs beam UTC(OP) H-maser

8 The clock ensemble at SYRTE GNSS GNSS Telecom GPS LAB 1 LAB 2 Cs beam UTC(OP) H-maser FO1 Cs fountain Cryo DRO FO2 dual Rb & Cs fountain FOM transportable Cs fountain Microwave clocks

9 The clock ensemble at SYRTE GNSS GNSS Telecom GPS LAB 1 LAB 2 Cs beam UTC(OP) Optical frequency measurement Optical frequency combs H-maser Spectral hole burning FO1 Cs fountain Cryo DRO FO2 dual Rb & Cs fountain FOM transportable Cs fountain Microwave clocks

10 The clock ensemble at SYRTE GNSS GNSS Telecom Coherent optical fiber links Fiber-based TF dissemination GPS LAB 1 LAB 2 1.5um ultrastable laser Cs beam UTC(OP) Optical frequency measurement Optical frequency combs H-maser Spectral hole burning FO1 Cs fountain Cryo DRO FO2 dual Rb & Cs fountain FOM transportable Cs fountain Microwave clocks

11 The clock ensemble at SYRTE GNSS GNSS Telecom Coherent optical fiber links Fiber-based TF dissemination GPS LAB 1 LAB 2 1.5um ultrastable laser Cs beam UTC(OP) Optical frequency measurement Optical frequency combs H-maser Spectral hole burning FO1 Cs fountain Cryo DRO FO2 dual Rb & Cs fountain FOM transportable Cs fountain Microwave clocks

beam Optical frequency measurement Optical

12 The clock ensemble at SYRTE GNSS GNSS Telecom Coherent optical fiber links GPS Fiber-based TF dissemination 1.5um ultrastable laser LAB 1 LAB 2 UTC(OP) Cs beam Optical frequency measurement Optical frequency combs Spectral hole burning H-maser Optical clocks FO1 Cs fountain 698 nm ultrastable laser Cryo DRO FOM transportable Cs fountain nm ultrastable laser FO2 dual Rb & Cs fountain Microwave clocks Sr optical lattice clocks Hg optical lattice clock

13 Outline 1. Experiments with atomic fountains 1. Variation of fundamental constants 2. Searching for dark matter candidates 2. The mercury optical lattice clock at SYRTE 1. Why mercury 2. Experimental setup 3. Error budget 3. Optical clock comparisons 1. Sr/Cs local comparisons 2. Sr/Sr distant comparisons 3. Hg/Sr local comparison 4. Perspectives

14 Experiment with atomic fountains: testing EEP with clocks

Experiments with atomic fountains Cryo Sapphire Ocillator (with UWA) Atomic quality factor: Typical performances: Stability: Cs: 6 x 10-14 @ 1s Rb: 4.

, Metrologia 51, 108 (2014) the LNE-SYRTE reference hydrogen maser condary Frequency Standard from October is H-maser 1400XXX in the BIPM clock correspond to

Fractional frequency instability characterized in terms of the Allan standard deviation observed with the FO2-Rb Secondary Frequency Standard and the metrology chain of

15 Experiments with atomic fountains Cryo Sapphire Ocillator (with UWA) Atomic quality factor: Typical performances: Stability: Cs: 6 x 1s Rb: 4.5 x 1s J Guéna et al., IEEE TUFFC 59, 391 (2012) J Guéna et al., Metrologia 51, 108 (2014) the LNE-SYRTE reference hydrogen maser condary Frequency Standard from October is H-maser 1400XXX in the BIPM clock correspond to interruptions of FO2-Rb for efurbishing the set-up. Fig. 7. Fractional frequency instability characterized in terms of the Allan standard deviation observed with the FO2-Rb Secondary Frequency Standard and the metrology chain of Fig. 5. Red squares: Instability obtained with FO2-Rb operated at high atom number. The first points reflect the dynamics of the digital servo system locking the 6.8 GHz microwave signal to the atomic transition. For > 1000 s, the phase lock loop of the ultra-stable reference to the H-maser is effective. Therefore, data reflects the behavior of the H-maser Uncertainty: Cs: 2.1 x Rb: 3.2 x 10-16

16 Variation of fundamental constants J Guéna et al., Phys. Rev. Lett. 109, (2012) M Abgral et al., C. R. Phys. 16, 461 (2015) d ν ln( ν d dt Rb Cs ν ln( ν Rb Cs ) 17 = ( 10.7 ± 4.9) 10 yr 16 ) = C + (0.8 ± 0.9) 10 cos[ Ω ( t t 1 perihelion )] c² d du ν ln( ν Rb Cs ) = ( 4.7 ± 5.3) 10 7

17 Variation of fundamental constants J Guéna et al., Phys. Rev. Lett. 109, (2012) M Abgral et al., C. R. Phys. 16, 461 (2015) d ν ln( ν d dt Rb Cs ν ln( ν Rb Cs ) 17 = ( 10.7 ± 4.9) 10 yr 16 ) = C + (0.8 ± 0.9) 10 cos[ Ω ( t t 1 perihelion )] c² d du ν ln( ν Rb Cs ) = ( 4.7 ± 5.3) 10 7

18 Variation of fundamental constants J Guéna et al., Phys. Rev. Lett. 109, (2012) M Abgral et al., C. R. Phys. 16, 461 (2015) d ν ln( ν d dt Rb Cs ν ln( ν Rb Cs ) 17 = ( 10.7 ± 4.9) 10 yr 16 ) = C + (0.8 ± 0.9) 10 cos[ Ω ( t t 1 perihelion )] c² d du ν ln( ν Rb Cs ) = ( 4.7 ± 5.3) 10 7 Differential redshift test β ( 87 Rb) β ( 133 Cs) = ( 4.7 ± 5.3) 10 7 Variation of constants with gravity d dt ln( α 0.49 ( m q / Λ QCD ) ) = ( 4.7 ± 5.3) yr 1

19 Searching for Dark matter candidates using hyperfine freq. comparisons arxiv: Simplest version of post-gr model (scalar tensor theory) : c 2 V ( )=2 m 2 2 L int = d e F 2 ~ 4µ 0 self-interaction coupling to EM Non-zero mass implies oscillation at Compton frequency: +3H +! 2 = 4 G c 2 L int! = m c 2 /~ and no pressure (candidate for DM). We can fix φ0 DM.

20 Searching for Dark matter candidates using hyperfine freq. comparisons arxiv: Simplest version of post-gr model (scalar tensor theory) : c 2 V ( )=2 m 2 2 L int = d e F 2 ~ 4µ 0 self-interaction coupling to EM Non-zero mass implies oscillation at Compton frequency: +3H +! 2 = 4 G c 2 L int! = m c 2 /~ and no pressure (candidate for DM). We can fix φ0 DM. Coupling to EM implies violation of EEP at the frequency of φ: ( )= (1 + d e ) T. Damour and J. F. Donoghue, Phys. Rev. D 82, (2010)

21 Analysing 6 years of Cs vs. Rb arxiv: We look for oscillation in the Cs/Rb frequency ratio: Log(P) Fit to data (LS + Bayes MC): A + S sin(! t)+c cos(! t) Compute power and its variance: P = N(C 2 + S 2 )/(4 2 ) Log(ω/rad s -1 )

Analysing 6 years of Cs vs. Rb arxiv:1604.8514 We look for oscillation in the Cs/Rb frequency ratio: Log(P) Fit to data (LS + Bayes MC): A + S sin(! t)+c cos(!

22 Analysing 6 years of Cs vs. Rb arxiv: We look for oscillation in the Cs/Rb frequency ratio: Log(P) Fit to data (LS + Bayes MC): A + S sin(! t)+c cos(! t) Compute power and its variance: P = N(C 2 + S 2 )/(4 2 ) Log(ω/rad s -1 ) No detection, but limit to coupling as a function of mass: Log(d e (d m -d g )) Log(m ϕ c 2 /ev) - Plot with full coupling. - Complementary to WEP violation - When limited to EM coupling this is the most stringent test. K. Van Tilburg, et al., PRL 115, (2015) A. Arvanitaki,et al. PRL 116, (2016)

23 t Rabi = 260 ms FWHM: 3.4 Hz Beyond atomic fountains: Optical lattice clocks

24 The mercury optical lattice clock - Fermionic isotope 199 Hg has I=1/2 - Weak sensitivity to black body radiation shift (Sr/30, Yb/15) - Clock transition frequency sensitive to time variation of α - Excellent prospects for reproducibility at room T H. Katori et al., Phys. Rev. Lett. 91, (2003) Hachisu et al., Phys. Rev. Lett. 100, (2008) L. Yi et al., Phys. Rev. Lett (2011) A. Ludlow et al., Rev. Mod. Phys. 87, 637 (2015)

25 The mercury optical lattice clock - Fermionic isotope 199 Hg has I=1/2 - Weak sensitivity to black body radiation shift (Sr/30, Yb/15) - Clock transition frequency sensitive to time variation of α - Excellent prospects for reproducibility at room T t Rabi = 260 ms FWHM: 3.4 Hz Rabi Spectroscopy : FWMH nm Q at H. Katori et al., Phys. Rev. Lett. 91, (2003) Hachisu et al., Phys. Rev. Lett. 100, (2008) L. Yi et al., Phys. Rev. Lett (2011) A. Ludlow et al., Rev. Mod. Phys. 87, 637 (2015)

26 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC DAQ 3D MOT Pumping Hg reservoir

27 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC DAQ 3D MOT Pumping Hg reservoir Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

28 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ 3D MOT Pumping Hg reservoir Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

29 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ Lattice build-up cavity 3D MOT Pumping Hg reservoir Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

30 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

31 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm FIBER COMB (for comparison) Enh SHG BBO 266 nm Enh SHG ppslt 531nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

32 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm FIBER COMB (for comparison) Enh SHG BBO 266 nm Enh SHG ppslt 531nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

33 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker EM CCD Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm FIBER COMB (for comparison) Enh SHG BBO 266 nm Enh SHG ppslt 531nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

34 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker EM CCD Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm FIBER COMB (for comparison) Enh SHG BBO 266 nm Enh SHG ppslt 531nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

35 Experimental setup: UV challenge 1. Cooling 2. Trapping 3. Selection 4. Interrogation 5. detection PC Enh SHG LBO 326 nm Ti:Sa laser 725 nm Wavemeter unc. 10 MHz DAQ USC 3 x flicker EM CCD Lattice build-up cavity 3D MOT Pumping Hg reservoir PDH Fiber laser nm FIBER COMB (for comparison) Enh SHG BBO 266 nm Enh SHG ppslt 531nm Sat absorption Enh SHG BBO 254 nm Seed ECDL 1015 nm Simple SHG ppln 507 nm Fiber ampli 15 W

36 Mercury clock: uncertainty budget Corr. (10-17 ) Unc. (10-17 ) Second order Zeeman Cold collisions Background gas Lattice light shift linear Lattice light shift non BBR Probe light shift AOM chirp TOTAL

37 Mercury clock: uncertainty budget Corr. (10-17 ) Unc. (10-17 ) Second order Zeeman Cold collisions Background gas Lattice light shift linear Lattice light shift non BBR Probe light shift AOM chirp y/yold 1 (10 15 ) TOTAL

38 Mercury clock: uncertainty budget Corr. (10-17 ) Unc. (10-17 ) Second order Zeeman Cold collisions Background gas Lattice light shift linear Lattice light shift non BBR Probe light shift AOM chirp y/yold 1 (10 15 ) TOTAL Most accurate: 3.6 x 10-16

39 Mercury clock: uncertainty budget Corr. (10-17 ) Unc. (10-17 ) Second order Zeeman Cold collisions Background gas Lattice light shift linear Lattice light shift non BBR Probe light shift AOM chirp y/yold 1 (10 15 ) TOTAL Most accurate: 3.6 x Light shift is dominant -Some systematics are limited by statistics -For a few effects only theoretical estimation available -Best clocks in the : room for improvement!

40 Main systematic: lattice light shift - Differential Measurement Uref = 56 ER 362nm) U 1 from 56 to 25 E R LLS = 1/2[ + (U L ) + (U REF )+ + (U L ) (U REF )] - Magic wavelength determination ν magic = (21) MHz Good agreement with RIKEN group Yamanaka et al., PRL 114, (2015) - Correction at operating point of the clock (56 E R ) (4 ± 13.8) x from linear term (-6 ± 3.6) x from computed unresolved non linear contributions Katori et al., PRA 91, (2015)

Absolute frequency of the Sr clock transition 4 2015 2016 ν Sr /Hz - 429228004229870 3.5 3 2.

41 Absolute frequency of the Sr clock transition ν Sr /Hz MJD The future of clock-based tests: Optical to optical clock comparisons

42 Clock comparisons at SYRTE CSO + H-maser + Fountains USC 1550 nm Fiber comb f 0 mixed-out AOM AOM Hg USC 1062 nm Sr USC 698 nm

43 International measurements of Sr/Cs Latest measurement at SYRTE: arxiv: ν Sr /Hz MJD SYRTE PTB JILA Univ. Tokyo NICT NMIJ NIM

44 International measurements of Sr/Cs Latest measurement at SYRTE: arxiv: ν Sr /Hz MJD SYRTE PTB JILA Univ. Tokyo NICT NMIJ NIM - Excellent level of reproducibility at the international level - Agreement between the two best measurements at a few Large level arm (> 10 years) for testing EEP (mid /year) - Optical/Microwave ratio limited by the accuracy of atomic fountains

45 All-optical remote clock comparison SYRTE, LPL, PTB collaboration 1E-15 total Allan deviation σ y (τ) 1E-16 1E averaging time τ (s) C Lisdat et al., arxiv: (2015)

46 All-optical remote clock comparison SYRTE, LPL, PTB collaboration 1E-15 total Allan deviation σ y (τ) 1E-16 1E averaging time τ (s) - First long distance or international clock comparison with a fibre link - 10 times more resolution, and orders of magnitude faster than satellite comparison ( resolution after a few 1000 s) - record agreement between distant clocks (4±5) first link of a future backbone of fibre links in France/Europe C Lisdat et al., arxiv: (2015)

47 Mercury vs Sr: arxiv: Comparison stability (10-15 ): Best run: 1s Avg over 10 days: 1s Fract. Unc. (units of ) Sr clock 4.1 Hg clock 16.7 Optical-to-optical frequency ratio Link + Comb 1 U B (syst. total) 18 Fractional uncertainty: 1.8x10-16 U A (stat.) 5.0

48 Mercury vs Sr: arxiv: Comparison stability (10-15 ): Best run: 1s Avg over 10 days: 1s Fract. Unc. (units of ) Sr clock 4.1 Hg clock 16.7 Optical-to-optical frequency ratio Link + Comb 1 U B (syst. total) 18 Fractional uncertainty: 1.8x10-16 U A (stat.) Frequency ratio very sensitive to α variations - Uncertainty below the realisation of SI second

49 v Hg /v Sr : best reproduced physical quantity? Tuymenev et al., arxiv: (2016) 2015 Yamanaka et al., PRL 114, (2015) - Completely independent measurement - Beyond (slightly) current SI second 2016

50 v Hg /v Sr : best reproduced physical quantity? Tuymenev et al., arxiv: (2016) 2015 Yamanaka et al., PRL 114, (2015) - Completely independent measurement - Beyond (slightly) current SI second Great reproducibility at level: - similar to Sr/Cs - better than Yb/Sr - Can and will be used for testing GR

51 Summary & Perspectives

52 Perspectives - Fountains have >10 more years of data taking for TAI - Redefinition of the SI second - Exploiting optical clocks for fundamental physics tests - Towards accuracy Hg remains an excellent candidate for a reproducible room temperature frequency standard Measurement of non-linear lattice shifts (limitation?) - Valuable Hg/ frequency ratios Local Plenty of yet unmeasured frequency ratios are now available via optical fiber link networks in Europe (Hg/Yb + (E2), Hg/Yb + (E3), Hg/Sr + ) ACES

53 People & bibliography - Atomic fountains: M Abgrall, J Guéna, S Bize J Guéna et al., IEEE TUFFC 59, 391 (2012) J Guéna et al., Metrologia 51, 108 (2014) - Theory and GR tests: P Wolf, P Delva A Hees et al., arxiv: (2016) J Guéna et al., Phys. Rev. Lett. 109, (2012) M Abgral et al., C. R. Phys. 16, 461 (2015) - Optical to optical comparisons: Combs: Y Le Coq, R Le Targat Strontium: J Lodewyck, R Le Targat Mercury: L De Sarlo, S Bize C Lisdat et al., arxiv: (2015) R Tyumenev et al., arxiv: (2016)

54 Thank you for your attention!

Clock tests of space-time variation of fundamental constants

1 Systèmes de Référence Temps-Espace Clock tests of space-time variation of fundamental constants J. Guéna, S. Bize, M. Abgrall, L. De Sarlo, Ph. Laurent, Y. Le Coq, R. Le Targat, J. Lodewyck, P. Rosenbusch,