Perspectives on the Quantum World Jun Ye, JILA, NIST & - - PowerPoint PPT Presentation

Optical Atomic Clocks – Opening New Perspectives on the Quantum World

Jun Ye, JILA, NIST & University of Colorado 26th CGPM Open Session, November 16 2018

Credit: NIST

New physics on table top Many-body dynamics Quantum sensing Ultra-coherence

7 SI Base Units

m cd mol

K A

s

kg

e

133Cs

NA C kB h Kcd

Almost all units, base or derived, can be traced to time

• Fundamental laws & constants

are our units

• “For all times, For all people.”
• “For all times, For all people.”

Probes for Fundamental Physics

Network of clocks (10-21): long baseline interferometry Standard Model  SI units But, it is INCOMPLETE :

• Dark matter & energy
• Matter-antimatter asymmetry

Space-time ripples Unruly spiral galaxies Dark matter halo

Credit: NASA Credit: NASA Credit: NASA

Kolkowitz et al., Phys. Rev. D 94, 124043 (2016). Kómár et al., Nat. Phys. 10, 582 (2014);

Time Scales

Credit: NASA

Life of the Universe: 15 billion years (1018 s） 1,000,000,000,000,000,000 seconds Quantum pendulum period: 10-15 s 0.000 000 000 000 001 second

The geometric mean ~30 s Sr atoms:

• 1S0 ↔

3P0 (160 s)

• Q ~ 1017

Quantum Certainty and Uncertainty

|g> |e>

Quantized transition frequency

12 3 9 10 11 8 7 1 2 4 5 6

|e> |g> 1 2 𝑓𝑗𝜚|𝑓 + |𝑕

The Strength of MANY – when you are certain

12 3 9 10 11 8 7 1 2 4 5 6

Quantum Phase Noise of Atoms Classical Phase Noise of Probe Laser

DfSQL = 1 N rad

Quantization of Motion & Interaction (Quantum Certainty)

Optical Coherence time ~ 1 minute

JILA PTB Matei et al., PRL 118, 263202 (2017); Zhang et al., PRL 119, 243601 (2017). Signal amplitude

0.1 0.2 0.3 0.4 0.5

Beat frequency (Hz)

0.10 0.05

• 0.10 -0.05

Stability: 4 x 10-17

A ruler for the Universe

Laser is the Central Ruler of Time & Space

Hänsch & Hall: Frequency comb

Cooling Atoms with Light Chu, Cohen-Tannoudji, Phillips

Holding Atoms in a Magic Light Bowl

Ye, Kimble, Katori, Science 320, 1734 (2008).

|g> |e>

698 nm

87Sr

Incident laser

g e

Laser beam Udipole

Clock laser

Ashkin, …

|g> |e>

Quantizing the Doppler Effect

Kolkowitz et al., Nature 542, 66 (2017).

T = 1 mK

Quantum State Control

• Doppler shift = 0 (motion quantized)
• Precision improvement by N1/2

|g>

trap

ω

|e> Ludlow et al., Rev. Mod. Phys. 87, 647 (2015). JILA Sr Clock II : 2.1 x 10-18 Nicholson et al., Nature Comm. 6 (2015).

• 15
• 10
• 5

5 10 15 0.2 0.4 0.6 0.8

Detuning (Hz) Excitation Fraction

Linewidth ~ Hz

Haroche, Wineland

Atomic Clock: Sensors of Space-time

10-20

Nicholson et al., Nature Comm. 6 (2015).

t

Poli et al. La rivista del Nuovo Cimento, 36, 555 (2013).

Quantization along x & y

3D Fermi Gas Clock

Scaling up the Sr quantum clock: 1 million atoms (100 x 100 x 100 cells)

Pauli Exclusion Principle  1 atom (clock) per site

Coherence 160 s Precision 3 x 10-20 Hz-1/2

Quantum gases: Cornell, Ketterle, Wieman; Jin

A Fermi Gas Mott Insulator Clock

𝑦 𝑧 𝑨

Clock laser frequency (kHz) Excitation fraction Nuclear spin 9/2 |g> |e>

Goban et al., Nature 563, 369 – 373 (2018).

Interaction quantized

Long Atom-Light Coherence

• S. Campbell et al., Science 358, 90 (2017).

Quality factor: 8 x 1015 Atom-Light coherence: 10 s

Laser detuning (Hz) Excitation fraction

6s, 83 mHz

Limit: photon scattering ; need shallow lattices

A Fermi Band/Mott Insulator Clock

q 𝜀𝜄 < 3𝑝 × 10−5

𝑏 =

𝜄

lclock

Kolkowitz et al., Nature 542, 66 (2017); Bromley et al., Nature Phys. 14, 399 (2018).

t

lclock

t

𝑓𝑗2𝜌 𝑏/𝜇𝑑𝑚𝑝𝑑𝑙 = 1 𝑓𝑗2𝜌 𝑏/𝜇𝑑𝑚𝑝𝑑𝑙 ≠ 1

Clock under a Microscope

Imaging resolution ≈ 1 μm ≈ 2 lattice sites

Marti et al., Phys Rev Lett 120, 103201 (2018).

𝛼𝐶𝑦

10-19 10-18 10-17 102 104 103 10 Average time (s) Allan Deviation

2.5⨉10-19 @ 3 hours

Quality factor 8 x 1015

Gravitational Potential & Atomic Coherence

Extreme spatial resolution & precision

• 10 μm height: 10-21 effect

• E. Marti (Stanford U)
• S. Bromley (U. Durham)
• W. Zhang (NIST)
• S. Campbell (UC Berkeley)
• S. Kolkowitz (U. Wisconsin)
• X. Zhang (Peking U.)
• T. Nicholson (NUS)
• M. Bishof (Argonne)
• B. Bloom (Atom Compute)
• M. Martin (Los Alamos)
• J. Williams (JPL/Caltech)
• M. Swallows (Honeywell)
• S. Blatt (MPQ, Garching)
• A. Ludlow (NIST)
• G. Campbell (JQI, NIST)
• T. Zelevinsky (Columbia U.)
• Y. Lin (NIM)
• M. Boyd (AO Sense)
• J. Thomsen (U. Copenhagen)
• T. Zanon (Univ. Paris 6)
• S. Foreman (U. San Fran)
• X. Huang (WIPM)
• T. Ido (NICT Tokyo)
• X. Xu (ECNU)
• T. Loftus (Honeywell)
• T. Bothwell
• D. Kedar
• C. Kennedy
• W. Milner
• E. Oelker
• J. Robinson
• A. Goban
• R. Hutson
• C. Sanner
• L. Sonderhouse

Collaboration: NIST Time & Frequency, PTB (Riehle, Sterr, Legero) Theory: A. M. Rey, M. Safronova, P. Julienne,

• M. Lukin, P. Zoller, …

Sr optical clock – a big playground Current Sr Group

Laser is the Central Ruler of Time & Space

Length is linked to Time via c

Laser Cavity

Cavity length L ~ 1 m  DL ~ 10-16 m (size of a nucleus: 10-14 m)

Laser C

Hänsch & Hall: Optical frequency comb

Clock Meets Atomic Interactions

U t >> 1

Quantum fluctuations correlated Martin et al., Science 341, 632 (2013). Zhang et al., Science 345, 1467 (2014). U U

Fractional Shift (10-15) Excitation angle

• 2
• 1

1

×

|↑↓ + |↓↑ |n1 n2 ‒ |n2 n1

ni nj

Table-top search for new physics Many-body dynamics Quantum sensing

Credit: Ye Group Credit: NIST Credit: Ye Group

Atomic Clock: Sensors of Space-time

Important innovations:

 Higher Q optical transitions  New laser phase control:

• ptical coherence > 1 s

 Trapped atoms/ions: high N, long coherence  Optical frequency comb

10-20

Nicholson et al., Nature Comm. 6 (2015).

 Current accuracy ~10-18 : gravitational redshift 1 cm  Quantum many-body and coherence

t

Poli et al. La rivista del Nuovo Cimento, 36, 555 (2013).

Quantization along x & y