Matt Jones Precision Tests of Fundamental Physics using Strontium Clocks.
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Transcript of Matt Jones Precision Tests of Fundamental Physics using Strontium Clocks.
Outline
1. Atomic clocks
2. The strontium lattice clock
3. Testing fundamental physics
4. Entanglement and clocks
Atomic clocks
• The second“The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium 133 atoms (at 0K).”
• The metre:“The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.”
Current accuracy: 1 × 10-15
Ramsey interferometry
€
ψ = 12
0 + 1( )
€
ψ = 12
0 + ei(ω−ω0 )t 1( )
€
ψ =α 0 + β 1
€
ψ =0
split recombine
t
F=4
F=39.2 GHz
Strontium lattice clock
1S0
1P1
461 nm = 32 MHz
3P 2
1
0
698 nm = 1 mHz
M. Takamoto et al., Nature 435, 321 (2005)
Optical clockwork
Oscillators:
Lasers need <1 Hz linewidth!
Ye group JILA
Counters:
Femtosecond frequency comb
(Nobel Prize 2005)
MPQ
/Bath University
Optical atomic clocks
Courtesy of H. Margolis, NPL
Current state-of-the-art:
Single ions: 1 × 10-17
Lattice clocks: 1 × 10-16
C. W. Chou et al., quant-ph/0911.4572 (2010)
M. D. Swallow et al., quant-ph/1007.0059 (2010)G. K. Campbell et al., Metrologia 45, 539 (2008)
Testing fundamental physics
•Relativity
10-16 is a difference in height of just 1m
•Time variation of fundamental constants
•Non-Newtonian short range forces
Motivation
•Cosmology
Some models predict that α and µ were different in the early universe
•Unified field theories
Constants couple to gravity
Implies a violation of Local Position Invariance
Principle
Measure how ωSr/ωCs varies with time
€
δωSrωSR
= KrelSr δαα
€
δωCsωCs
= KrelCs + 2( )
δαα
+δμμ
Lattice clocks at Durham
EPSRC proposal:
“Entanglement-enhanced enhanced optical frequency metrology using Rydberg states”
Collaborators:National Physical LaboratoriesUniversity of Nottingham
Panel sits tomorrow!!
Lattice clocks at Durham
Normalclock
Entangled clock€
ψN =12
0 + 1( ) ⎛ ⎝ ⎜
⎞ ⎠ ⎟N
€
ψN =12
01,02 ,K 0N + 11,12,K1N( )€
σ ∝1/ N
€
σ ∝1/N
Summary
•Atomic clocks provide the most accurate measurements
•Optical atomic clocks have lead to a new frontier
•This can be used for precision tests of our fundamental theories
References
Fountain clocks
R. Wynands and S. Weyers, Metrologia 42 (2005) S64-S79
Fundamental physics tests S. Blatt et al., Phys. Rev. Lett. 100, 140801 (2008) P. Wolf et al., Phys. Rev. A 75, 063608 (2007)F. Sorrentino et al., Phys. Rev. A 79, 013409 (2009)
Optical clocksM. Takamoto et al., Nature 435, 321 (2009)C. W. Chou et al., quant-ph/0911.4572 (2010)M. D. Swallow et al., quant-ph/1007.0059 (2010)G. K. Campbell et al., Metrologia 45, 539 (2008)