searches for new physics with atoms atoms and molecules and … · 2020-06-03 · beam experiments,...

Searches for new physics with Searches for new physics with Searches for new physics with Searches for new physics with

atoms atoms atoms atoms and moleculesand moleculesand moleculesand molecules

Marianna Safronova

SEMINAR ON PRECISION PHYSICS AND FUNDAMENTAL SYMMETRIES

Department of Physics and Astronomy, University of Delaware, DelawareJoint Quantum Institute, NIST and the University of Maryland, College Park, Maryland

100 years ago

We though we knew

everything about the Universe

1920

Standard model

+ fundamental physics postulates

According to the Standard Model

Our Universe can not exist !

“Normal”matter

We don’t know what most (95%) of the Universe is!

??

< 5%

When we compare experiments, what do we assume?

Lorentz invariance

rotations

boosts

Position invarianceWeak equivalence principle

DEFINITELY DEFINITELY DEFINITELY DEFINITELY

HIGHLY HIGHLY HIGHLY HIGHLY

INCOMPLETEINCOMPLETEINCOMPLETEINCOMPLETE

All of our assumptions are expected to be wrong

Lorentz invariance

rotations

boosts

Position invarianceWeak equivalence principle

Extraordinary progress in the control of atoms and ions

300K

pKTrappedAtoms are now: Ultracold

3D

Image: Ye group and Steven Burrows, JILA

Precisely controlled

1997 Nobel PrizeLaser cooling and

trapping

2001 Nobel PrizeBose-Einstein

Condensation

2012 Nobel prizeQuantum control

2005 Nobel PrizeFrequency combs

WE CAN SEARCH FOR

VIOLATIONS OF ALL OF THESE

ASSUMPTIONS WITH PRECISION

MEASUREMENTS

GOAL: DISCOVER NEW PHYSICS

VERY WIDE SCOPE OF AMO NEW

PHYSICS SEARCHES

RMP 90, 025008 (2018)

Review chapters:

1. Search for variation of fundamental constants

Atomic clocks & spectroscopy, astrophysics studies of atomic and molecular spectra,

molecular frequency measurements

2. Precision tests of Quantum Electrodynamics

Precision frequency measurements with electrons, lightest atoms (H, He, etc.), muonic

hydrogen, highly-charged ions, exotic atoms, others

3. Atomic parity violationBeam experiments, cold trapped atoms and ions.

Need heavy atoms: Cs, Tl, Fr, Ra+, Ra ,… molecules in the future

4. Time-reversal violation: electric dipole moments and related phenomena

Cold molecular beams, trapped molecular ions, future: ultracold atoms, laser-cooled

(polyatomic) molecules

5. Tests of the CPT theorem, matter-antimatter comparisons

Proton/antiproton, single ion traps, (cold) antihydrogen

6. Searches for exotic spin-independent interactions

Future: ultracold atoms as force sensors, atom interferometry, etc.

6. Laboratory searches for exotic spin-dependent interactions

Magnetometry (spin-precession), precision theory/experiment comparisons

(frequencies), networks or magnetometers and clocks, precision isotope shift measurements

7. Searches for light dark matter (all precision tools)

• Microwave cavity axion experiments

• Spin-precession axion experiments

• Radio axion searches

• Atomic clocks and accelerometers, and spectroscopy

• Exotic spin-dependent forces due to axions/ALPs

• Magnetometer and clock networks for detection of transient DM signals

8. General relativity and gravitation

Atom interferometry

9. Lorentz symmetry testsAtomic clocks, magnetometers, quantum control of trapped ions, spectroscopy, rotating cavities

10.Search for violations of quantum statistics

Search for Pauli-forbidden atomic or molecular transitions

NEW PHYSICS SEARCHES WITH

ATOMIC CLOCKS

GPS satellites:

microwave

atomic clocks

airandspace.si.edu

Optical atomic clocks will not lose one second in

30 billion years

Ingredients for a clock

1. Need a system with periodic behavior: it cycles occur at constant frequency

NOAA/Thomas G. Andrews

2. Count the cycles to produce time interval

3. Agree on the origin of time to generate a time scale

Ludlow et al., RMP 87, 637 (2015)

Ingredients for an atomic clock

1. Atoms are all the same and will oscillate at exactly

the same frequency (in the same environment):

you now have a perfect oscillator!

2. Take a sample of atoms (or just one)

3. Build a laser in resonance with this atomic

frequency

4. Count cycles of this signal

Ludlow et al., RMP 87, 637 (2015)

171Yb+

ION

How optical atomic clock works

The laser is resonant with the atomic transition. A correction signal is derived from atomic spectroscopy that is fed back to the laser.

From: Poli et al. “Optical atomic clocks”, La rivista del Nuovo Cimento 36, 555 (2018) arXiv:1401.2378v2

An optical frequency synthesizer (optical frequency comb) is used to divide the optical frequency down to countable microwave or radio frequency signals.

2

π

2

π

Me

asu

re

po

pu

lati

on

Init

iali

ze

wait

1 2

2

+

Ramsey scheme

http://www.nist.gov/pml/div689/20140122_strontium.cfm

JILA Sr clock2×10-18

Applications of atomic clocks

Image Credits: NOAA, Science 281,1825; 346, 1467, University of Hannover, PTB, PRD 94, 124043, Eur. Phys. J. Web Conf. 95 04009

GPS, deep space probes

Very Long Baseline Interferometry Relativistic geodesy

Quantum simulation

Searches for physics beyond the Standard ModelDefinition of the second

10 -18

1 cm

height

Gravity Sensor

Magma chamber

Atomic clocks can measure and compare

frequencies to exceptional precisions!

If fundamental constants change (now)

due to for various “new physics” effects

atomic clock may be able to detect it.

Search for physics beyond the standard model with atomic clocks

Frequency

will change BEYOND THE STANDARD MODEL?

Search for physics beyond the Standard Model with atomic clocks

Dark matter searches

Search for the violation of Lorentz invariance

Tests of the equivalence principle

Are fundamental constants constant?

ααααααααGravitational wave detection with atomic clocks PRD 94, 124043 (2016)

Image credit: NASA

Image credit: Jun Ye’s group

Theories with varying dimensionless fundamental constants

String theories

Other theories with extra dimensions

Loop quantum gravity

Dark energy theories: chameleon and quintessence models

…many others

Variation of fundamental constants

J.-P. Uzan, Living Rev. Relativity 14, 2 (2011)

Frequency of optical transitions

depends on the fine-structure constant α.α.α.α.

Measure the ratio of two optical clock frequencies to search

for the variation of α.α.α.α. Keep doing this for a while.

Some clocks are more sensitive to this effect than others

Sensitivity of optical clocks to αααα-variation/dark matter

0

2K

q

E=

2

2

1

1

1ln ( )K

v

t v tK

α

α

∂ ∂=

∂ ∂−

2

0 2

0

1E Eα

α

= + −

q

Enhancement factor

Need: large K for at least one for the clocks

Best case: large K2 and K1 of opposite sign for clocks 1 and 2

10010-18

Frequency ratio

accuracy

Test of αααα-variation

10-20

Easier to measure large effects!

Can calculate

with high accuracy

Observable: ratio of two clock frequencies

fiber

fiber

fb,Al

m frep+ fceo

1070 nm

laser

×2

×2

×2

×2

fb,HgHg+

n frep+ fceo

199Hg+

27Al+

9Be+

1126 nm

laser

Science 319, 1808 (2008)

Measure a ratio of Al+ clock

frequency to Hg+ clock

frequency

( )( )

+

+Al

Hgν

ν ( ) 0.01K Al+ =

( ) 2.9K Hg+ = −

Not sensitive to α-variation,

used as reference

Picture credit: Jim Bergquist

Sensitivity factors

Theories with varying dimensionless fundamental constants

String theories

Other theories with extra dimensions

Loop quantum gravity

Dark energy theories: chameleon and quintessence models

…many others

Variation of fundamental constants

J.-P. Uzan, Living Rev. Relativity 14, 2 (2011)

Frequency of optical transitions

depends on the fine-structure constant α.α.α.α.

Measure the ratio of two optical clock frequencies to search for the variation of αααα.

Dark matter can also cause variation of fundamental constants!

A. Derevianko and M. Pospelov, Nature Phys. 10, 933 (2014), A. Arvanitaki et al., PRD 91, 015015 (2015)

What dark matter affects atomic energy levels?

What dark matter can you detect if

you can measure changes in

atomic/nuclear frequencies to 20 digits?

0ν is a clock frequency

What is the experimental evidence for dark matter?

Rotation curves

Gravitational lensing Large-scale structures

CosmicMicrowaveBackground

410

δρ

ρ−≈

z =1100

WHY SEARCH FOR DARK MATTER?

Could elementary particles be cold dark matter?

Couple to plasma

No known particle can be cold dark matter – Need to search for new particles.

Particle of light

Hot dark matter

Decay quickly

Slide from Andrew Long’s 2018 LDW talk

EDM

searches

Simon Knapen, 2018 KITP

Dark matter density in our Galaxy >

is the de Broglie wavelength of the particle.

Then, the scalar dark matter exhibits coherence and behaves

like a wave

3

dBλ −

dBλ

Dilatons

A. Arvanitaki et al., PRD 91, 015015 (2015)

10101010----22222222 eV 10eV 10eV 10eV 10----12121212 eV eV eV eV µµµµeVeVeVeV eV GeVeV GeVeV GeVeV GeV

Ultralight dark matter has to be

bosonic – Fermi velocity for DM

with mass >10 eV is higher than

our Galaxy escape velocity.

10101010----22222222 eV 10eV 10eV 10eV 10----12121212 eV eV eV eV µµµµeVeVeVeV eV GeVeV GeVeV GeVeV GeV

How to detect ultralight dark matter with clocks?

It will make fundamental coupling constants and mass ratios oscillate

Dark matter field

couples to electromagnetic interaction and “normal matter”

Asimina Arvanitaki, Junwu Huang,

and Ken Van Tilburg, PRD 91,

015015 (2015)

Atomic energy levels will oscillate so clock frequencies will oscillate

Can be detected with monitoring ratios of clock frequencies over time

(or clock/cavity).

Ultralight dark matter

DM virial velocities ~ 300 km/s

photons

Dark matter

…

Then, clock frequencies will oscillate!

One oscillation per second

One oscillation per 11 days

Ultralight dark matter

DM virial velocities ~ 300 km/s

photons

Dark matter

Result: plot couplings de vs. DM mass mf

…

Then, clock frequencies will oscillate!

Measure clock frequency ratios:

Sensitivity factors to α-variation

Clock measurement protocols for the dark matter detection

Make N such measurements, preferably regularly spaced

Make a clock ratio measurement over time ∆τ


Detection signal: A peak with monochromatic frequency

in the discrete Fourier transform of this time series.

∆τ

τint

2

π

2

πwait m

ea

sure

ωφ

Need excellent SHORT term stability

For example 1 second



Single clock ratio measurement: averaging over time τ1


∆τ

τint

Detection signal: A peak with monochromatic frequencyin the discrete Fourier transform of this time series.

No more than one dark matter oscillationduring this time or use extra pulse sequence

Al least one dark matter oscillationduring this time

ωφ



Single clock ratio measurement: averaging over time τ1


∆τ

τint

Detection signal: A peak with monochromatic frequencyin the discrete Fourier transform of this time series.

Al least one dark matter oscillationduring this time

No more than one dark matter oscillation during

this time – actually need 4-5 measurement points

per DM oscillation to get correct frequency

ωφ

?

From PRL 120, 141101 (2018)

Present scalar DM limits

How to improve laboratory searches for the

variation of fundamental constants & dark matter?

Improve atomic clocks: better stability and uncertainty

Large ion crystalsIon chains 3D optical lattice clocks

Measurements beyond the quantum limit Entangled clocksImage credits: NIST, Innsbruck group, MIT Vuletic group, Ye JILA group

Improve atomic clocks: better stability and uncertainty

?M. S. Safronova, D. Budker, D. DeMille, Derek F. Jackson-Kimball,

A. Derevianko, and Charles W. Clark, Rev. Mod. Phys. 90, 025008 (2018).

How to improve laboratory searches for the

variation of fundamental constants & dark matter?

Clock sensitivity to all types of the searches for the variation of fundamental constants, including dark matter searches require as large enhancement factors K to maximize the signal.

0

2qK

E=

Enhancement factors for current clocks

0

1

K

-3

-6

( ) 0.8, 2 ( 1)K Hg K Yb E+= =

( ) ( )( )0.01, 0.06, 0.1K Al K Sr K Ca+ += = =( ) 0.3K Yb =

( ) 0.4K Sr+ =

( ) 2.9K Hg + = −

( )3 6K Yb E+ = −

Cavity K=1

Excellent stability N ~ 1000

Single ion clocks, N = 1

2

2

1

1

1ln ( )K

v

t v tK

α

α

∂ ∂=

∂ ∂−

Need very precise frequency

standards using NEW systems with

very large K

2

2

1

1

1ln ( )K

t tK

ν α

ν α

∂ ∂=

∂ ∂−

The Future: New Atomic Clocks

Nuclear clockSee talks by Ekkehard Peik

26 May & Peter Thirolf on June 1DAMOP (GPMFC workshop)

Clocks with ultracoldhighly charged ions

See talks by Piet Schmidt14 April & June 1 DAMOP (GPMFC workshop)

Science 347, 1233 (2015)

Probing the Relaxed Relaxion at the Luminosity and Precision FrontiersAbhishek Banerjee, Hyungjin Kim, Oleksii Matsedonskyi, Gilad Perez, Marianna S. Safronova,

arXiv:2004.02899

Relaxion-Higgs mixing angle as a function of the relaxion mass.

A relaxion window and the available parameter space for the light relaxion, current and projected constraints.

Cosmological relaxation of the

electroweak scale is an attractive

scenario addressing the gauge

hierarchy problem.

Its main actor, the relaxion, is a

light spin-zero field which

dynamically relaxes the Higgs

mass with respect to its natural

large value.

Talk by Gilad Perez on June 1

DAMOP 2020 (GPMFC workshop)

Recent theory progress in predicting properties of highly-charged ions

High-resolution Photo-excitation Measurements Exacerbate the Long-standing Fe XVII-Oscillator-Strength Problem

Steffen Kühn, Chintan Shah, José R. Crespo López-Urrutia, Keisuke Fujii, René Steinbrügge, Jakob Stierhof, Moto Togawa, Zoltán

Harman, Natalia S. Oreshkina, Charles Cheung, Mikhail G. Kozlov, Sergey G. Porsev, Marianna S. Safronova, Julian C. Berengut, Michael

Rosner, Matthias Bissinger, Ralf Ballhausen, Natalie Hell, SungNam Park, Moses Chung, Moritz Hoesch, Jörn Seltmann, Andrey S.

Surzhykov, Vladimir A. Yerokhin, Jörn Wilms, F. Scott Porter, Thomas Stöhlker, Christoph H. Keitel, Thomas Pfeifer, Gregory V. Brown,

Maurice A. Leutenegger, Sven Bernitt

To appear in Physical Review Letters on May 28, arXiv:1911.09707

Talks by Julian C. Berengut and José R. Crespo López-Urrutia next week, DAMOP 2020

Full correlation of 10 electrons – nothing else to include at this level of accuracy!

Experiment:


Accurate prediction of clock transitions in a highly charged ion with complex electronic structureC. Cheung, M. S. Safronova, S. G. Porsev, M. G. Kozlov, I. I. Tupitsyn, A. I. Bondarev, Phys. Rev. Lett. 124, 163001 (2020)

First configuration interaction calculation for 60 electrons with all shells open!

Talk by Charles Cheung at DAMOP 2020

Ir17+

Clock transitions???

E1 transitions???

Previous predictions (FAC):

E1 Transition Rate (s-1)

4f12 5s2 3F4 – 4f13 5s 3F4o 71 0.2

4f12 5s2 3F4 – 4f13 5s 3F3o 48 1.2

4f12 5s2 3F2 – 4f13 5s 1F3o 163 3

Hendrik Bekker, FAC calculations,

private communication vs. new results

Optical clocks based on the Cf15+ and Cf17+ ionsS. G. Porsev, U. I. Safronova, M. S. Safronova, P. O. Schmidt, A. I. Bondarev, M. G. Kozlov, I. I. Tupitsyn, arXiv:2004.05978


New project: Computer, calculate!

Automating atomic calculations & online

portal for atomic data, codes, and

computation

(see talk at DAMOP)

Classify atomic calculations by difficulty level

Group 1

Calculations we can

do “routinely”, with

default parameters

Can automate

1 – 2(3) valence

electrons

Group 2

Calculations that

require expert

knowledge

(3)/4-5 valence

electrons

or special cases

with more

valence electrons

Only calculations of wave

functions requires expert

knowledge

Group 3

No precision methods

exist: exponential

scaling with the

number of valence

electrons

Half-filled shells and

holes in shells

Method development in

progress, need new ideas –

machine learning

Email me at [email protected] what atoms/ions/properties to include!

New project at the University of Delaware: Computer, calculate!

Many new developments coming in the next 10 years!

Atomic clocks: Great potential for discovery of new physics

Need NEW IDEAS how to use quantum technologies for new physics searches

Entanglement as a resource?

Research scientist:Sergey Porsev

Graduate students:Charles Cheng, Aung Naing, Adam Mars, Hani Zaheer

COLLABORATORSCOLLABORATORSCOLLABORATORSCOLLABORATORS::::

Mikhail Kozlov, PNPI, RussiaIlya Tupitsyn, St. Petersburg University, RussiaJosé Crespo López-Urrutia, MPIK, Heidelberg Piet Schmidt, PTB, University of HannoverGilad Perez, The Weizmann Institute of Science, Israel

Online portal collaboration, Electrical & Computer Engineering:Prof. Rudolf Eigenmann, graduate student: Parinaz Barakhshan

Two new positions are expected to become available this summer: Postdoc and more senior Research Associate

Contact Marianna Safronova ([email protected]) for more information

Thorsten Schumm, TU WeinEkkehard Peik, PTBPeter Thirolf, LMU

Thorium nuclear clocks for fundamental tests

of physics

searches for new physics with atoms atoms and molecules and … · 2020-06-03 · beam experiments,...

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