[time-nuts] NIST Optical lattice clocks

Mark C. Stephens marks at non-stop.com.au
Thu May 30 05:13:23 EDT 2013

Just remember a lot of the Ytterbium comes from Australia, Jay ;)

According to Wikipedia, The optical clock based on it is exact to 17 digits after the decimal point!
I hope that doesn't mean it is time to trade my HP 5370B in shortly...
How do they measure down to these resolutions?

I thought they are already able to capture an atom in its own well?

Anyway, Hopefully the 'proof of concept' is there and start producing these really accurate clocks.
And stop the position wander on the GPS L1 satellites, that would be good..


My son just told me a good one: Who made a plane that cannot fly? The Wrong brothers..

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Jonatan Walck
Sent: Thursday, 30 May 2013 6:17 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] NIST Optical lattice clocks

Theory behind Ytterbium-based optical lattice clocks have been mentioned on this list before[1] but these results were new so I thought I'd share them.

NIST released a paper[2] (link to PDF[3] on the right side on arxiv) a week ago on results from two optical lattice clocks[4] with impressive results. Even by time-nuts standards.;)

"A measurement comparing these systems demonstrates an unprecedented atomic clock instability of 1.6 × 10−18 after only 7 hours of averaging."

The ADEV plot of one of these can be found on p. 14. Instead of posting more spoilers I'll let you all read the paper in all its glory amongst yourselves.

No mentions of when standards like these could start reporting to BIPM and contribute to TAI but I guess that's some way off. As someone mentioned to me regarding new atomic standards (at that time atomic
fountains) and mean time between failure: "Comes with physisist attached." Now that I think of it that might've been from slides presented by Ludlow himself.:)

// jwalck

[1] "[time-nuts] OT: The tick-tock of the optical clock ...."
[1] " An atomic clock with $10^{-18}$ instability"
[2] http://arxiv.org/pdf/1305.5869v1
[3] "Physicists Unveil World’s Most Precise Clock (And a Twin to Compare It Against)"
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