Optical Atomic Clocks – Opening New Perspectives on the Quantum World Jun Ye, JILA, NIST & University of Colorado 26 th CGPM Open Session, November 16 2018 Ultra-coherence Quantum sensing New physics on table top Many-body dynamics Credit: NIST
7 SI Base Units Almost all units, base or derived, can be traced to time 133 Cs s N A • Fundamental laws & constants e A are our units mol • “For all times, For all people.” • “For all times , For all people.” C k B m K cd kg h K cd
Probes for Fundamental Physics Space-time ripples Unruly spiral galaxies Dark matter halo Credit: NASA Credit: NASA Credit: NASA Standard Model SI units Network of clocks ( 10 -21 ): long baseline interferometry But, it is INCOMPLETE : • Dark matter & energy Kómár et al ., Nat. Phys. 10 , 582 (2014); • Matter-antimatter asymmetry Kolkowitz et al ., Phys. Rev. D 94 , 124043 (2016).
Time Scales Quantum pendulum period: 10 -15 s The geometric mean ~30 s 0.000 000 000 000 001 second Sr atoms: 1 S 0 ↔ 3 P 0 (160 s) • • Q ~ 10 17 Credit: NASA Life of the Universe: 15 billion years (10 18 s ） 1,000,000,000,000,000,000 seconds
Quantum Certainty and Uncertainty |e> 12 11 1 1 10 2 𝑓 𝑗𝜚 |𝑓 + | 9 3 2 4 8 7 5 6 |g> |e> Quantized transition frequency |g>
The Strength of MANY – when you are certain Quantum Phase Noise of Atoms Classical Phase Noise of Probe Laser 12 11 1 10 2 9 3 4 8 7 5 6 D f SQL = 1 rad Quantization of Motion & Interaction N (Quantum Certainty)
Laser is the Central Ruler of Time & Space 0.5 Optical Coherence time ~ 1 minute Matei et al ., PRL 118 , Stability: 263202 (2017); 4 x 10 -17 0.4 PTB Signal amplitude Zhang et al ., PRL 119 , JILA 0.3 243601 (2017). 0.2 0.1 0 -0.10 -0.05 0 0.05 0.10 Beat frequency (Hz) Hänsch & Hall: A ruler for the Universe Frequency comb
Cooling Atoms with Light Chu, Cohen-Tannoudji, Phillips
Holding Atoms in a Magic Light Bowl Ashkin , … Ye, Kimble, Katori, Science 320 , 1734 (2008). e Incident laser g Clock laser U dipole 87 Sr Laser beam |e> 698 nm |g> |e> |g>
Quantizing the Doppler Effect Kolkowitz et al ., Nature 542 , 66 (2017). T = 1 m K
Quantum State Control Haroche, Wineland Ludlow et al ., Rev. Mod. Phys. 87 , 647 (2015). |e> Linewidth 0.8 ~ Hz |g> Excitation Fraction 0.6 0.4 ω trap 0.2 0 -15 -10 -5 0 5 10 15 Detuning (Hz) • Doppler shift = 0 (motion quantized) • Precision improvement by N 1/2 JILA Sr Clock II : 2.1 x 10 -18 Nicholson et al ., Nature Comm. 6 (2015).
Atomic Clock: Sensors of Space-time Nicholson et al ., Nature Comm. 6 (2015). t 10 -20 Quantization along x & y Poli et al. La rivista del Nuovo Cimento, 36 , 555 (2013).
3D Fermi Gas Clock Quantum gases: Cornell, Ketterle, Wieman; Jin Scaling up the Sr quantum clock: Pauli Exclusion Principle 1 million atoms 1 atom (clock) per site (100 x 100 x 100 cells) Coherence 160 s Precision 3 x 10 -20 Hz -1/2
A Fermi Gas Mott Insulator Clock Goban et al ., Nature 563 , 369 – 373 (2018). Interaction quantized |e> 𝑦 𝑧 𝑨 |g> Nuclear spin 9/2 Excitation fraction 0 0 0 Clock laser frequency (kHz)
Long Atom-Light Coherence S. Campbell et al ., Science 358 , 90 (2017). Atom-Light coherence: 10 s 6s, 83 mHz Quality factor: 8 x 10 15 Excitation fraction Limit: photon scattering ; need shallow lattices Laser detuning (Hz)
A Fermi Band/Mott Insulator Clock l clock l clock t t 𝑓 𝑗2𝜌 𝑏/𝜇 𝑑𝑚𝑝𝑑𝑙 ≠ 1 𝑓 𝑗2𝜌 𝑏/𝜇 𝑑𝑚𝑝𝑑𝑙 = 1 Kolkowitz et al ., Nature 542 , 66 (2017); Bromley et al ., Nature Phys. 14 , 399 (2018). 𝜄 𝜀𝜄 < 3 𝑝 × 10 −5 q 𝑏 =
Clock under a Microscope Marti et al ., Phys Rev Lett 120 , 103201 (2018). 10 -17 2.5 ⨉ 10 -19 Allan Deviation @ 3 hours 10 -18 Quality factor 8 x 10 15 10 -19 𝛼𝐶 𝑦 10 4 10 2 10 3 10 Average time (s) Imaging resolution ≈ 1 μm ≈ 2 lattice sites
Gravitational Potential & Atomic Coherence Extreme spatial resolution & precision 10 μm height: 10 -21 effect
Sr optical clock – a big playground Current Sr Group T. Bothwell A. Goban E. Marti (Stanford U) A. Ludlow (NIST) D. Kedar R. Hutson S. Bromley (U. Durham) G. Campbell (JQI, NIST) C. Kennedy C. Sanner W. Zhang (NIST) T. Zelevinsky (Columbia U.) L. Sonderhouse S. Campbell (UC Berkeley) Y. Lin (NIM) S. Kolkowitz (U. Wisconsin) M. Boyd (AO Sense) W. Milner X. Zhang (Peking U.) J. Thomsen (U. Copenhagen) E. Oelker T. Nicholson (NUS) T. Zanon (Univ. Paris 6) J. Robinson M. Bishof (Argonne) S. Foreman (U. San Fran) B. Bloom (Atom Compute) X. Huang (WIPM) M. Martin (Los Alamos) T. Ido (NICT Tokyo) Collaboration: NIST Time & Frequency, J. Williams (JPL/Caltech) X. Xu (ECNU) PTB (Riehle, Sterr, Legero) M. Swallows (Honeywell) T. Loftus (Honeywell) S. Blatt (MPQ, Garching) Theory: A. M. Rey, M. Safronova, P. Julienne, M. Lukin, P. Zoller , …
Laser is the Central Ruler of Time & Space Cavity length L ~ 1 m D L ~ 10 -16 m (size of a nucleus: 10 -14 m) Laser Cavity Laser C Length is linked to Time via c Hänsch & Hall: Optical frequency comb
Clock Meets Atomic Interactions Martin et al ., Science 341 , 632 (2013). Zhang et al ., Science 345 , 1467 (2014). n j U U n i Quantum fluctuations correlated 1 U t >> 1 Fractional Shift (10 -15 ) 0 | n 1 n 2 ‒ |n 2 | ↑↓ + × n 1 |↓↑ -1 -2 Excitation angle
Credit: Ye Group Credit: NIST Quantum sensing Table-top search for new physics Many-body dynamics Credit: Ye Group
Atomic Clock: Sensors of Space-time Current accuracy ~10 -18 : Important innovations: gravitational redshift 1 cm Higher Q optical transitions Quantum many-body and coherence New laser phase control: optical coherence > 1 s Trapped atoms/ions: high N , long coherence Optical frequency comb Nicholson et al ., Nature Comm. 6 (2015). t 10 -20 Quantization along x & y Poli et al. La rivista del Nuovo Cimento, 36 , 555 (2013).
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