IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference
There's an interesting article in the December 2017 issue of IEEE Spectrum.
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
They have not incorporated the material into a working standard, but have
licensed the chemical fabrication technology to at least one manufacturer.
The idea is to make a chip-scale atomic frequency reference.
-- Tom, N5EG
Impressive, Ulrich
In a message dated 12/8/2017 12:41:23 PM Eastern Standard Time, tom.n5eg@gmail.com writes:
There's an interesting article in the December 2017 issue of IEEE Spectrum.
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
They have not incorporated the material into a working standard, but have
licensed the chemical fabrication technology to at least one manufacturer.
The idea is to make a chip-scale atomic frequency reference.
-- Tom, N5EG
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On Dec 8, 2017, at 10:38 AM, Ulrich Rohde via time-nuts time-nuts@febo.com wrote:
Impressive, Ulrich
In a message dated 12/8/2017 12:41:23 PM Eastern Standard Time, tom.n5eg@gmail.com writes:
There's an interesting article in the December 2017 issue of IEEE Spectrum.
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
They have not incorporated the material into a working standard, but have
licensed the chemical fabrication technology to at least one manufacturer.
The idea is to make a chip-scale atomic frequency reference.
-- Tom, N5EG
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I saw that about the N atom trapped inside a C60 molecule, but also
took note of the present cost of the material. I wonder how much is
going to be required to make a good standard.
Dana
On Fri, Dec 8, 2017 at 11:40 AM, Tom McDermott tom.n5eg@gmail.com wrote:
There's an interesting article in the December 2017 issue of IEEE Spectrum.
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
They have not incorporated the material into a working standard, but have
licensed the chemical fabrication technology to at least one manufacturer.
The idea is to make a chip-scale atomic frequency reference.
-- Tom, N5EG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
On Fri, 8 Dec 2017 09:40:29 -0800
Tom McDermott tom.n5eg@gmail.com wrote:
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
The original paper in question is [1]. As with the nitrogen vacancy
clocks, which also trap nitrogen within a Carbon lattice, these have the
drawback of quite high temperature coefficients, Harding et al measured 89ppm/K.
Attila Kinali
[1] "Spin Resonance Clock Transition of the Endohedral Fullerene 15N@C60",
by Harding, Zhou, Zhou, Myers, Ardavan, Briggs, Porfyrakis, Laird, 2017
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.140801
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson
Le 15 déc. 2017 à 14:06, Attila Kinali attila@kinali.ch a écrit :
On Fri, 8 Dec 2017 09:40:29 -0800
Tom McDermott tom.n5eg@gmail.com wrote:
Researchers at Oxford U. have fabricated an atomic reference based on
a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene").
The cage of carbon isolates the nitrogen from external electric fields,
and they've developed a method to also isolate it from external magnetic
fields.
The original paper in question is [1]. As with the nitrogen vacancy
clocks, which also trap nitrogen within a Carbon lattice, these have the
drawback of quite high temperature coefficients, Harding et al measured 89ppm/K.
I wonder if Cs-133 can be inserted into C-60 fullerene? If it could, then a primary reference on a chip might be possible.
Attila Kinali
[1] "Spin Resonance Clock Transition of the Endohedral Fullerene 15N@C60",
by Harding, Zhou, Zhou, Myers, Ardavan, Briggs, Porfyrakis, Laird, 2017
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.140801
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson
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George Bernard Shaw
On Fri, 15 Dec 2017 17:17:31 +0100
Mike Cook michael.cook@sfr.fr wrote:
The original paper in question is [1]. As with the nitrogen vacancy
clocks, which also trap nitrogen within a Carbon lattice, these have the
drawback of quite high temperature coefficients, Harding et al measured 89ppm/K.
I wonder if Cs-133 can be inserted into C-60 fullerene? If it could,
then a primary reference on a chip might be possible.
No, it wouldn't. It isn't the species of atom being used that defines
whether it is a primary standard or not, but rather that it is possible
to exactly calculate the frequency of the output given all disturbances.
It is possible to achieve this with Cs, Rb, Hg, Yb, Sr, ... it just depends
on how you do it.
The problem with the atom-in-fullerene is that the atom is not in
(a good approximation of) vacuum, as it is surrounded by a molecule
in close proximity. This means the surrounding atoms disturb the electrons
of the probed atom. This is what causes the large temperature dependence.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson