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[Lawrence London <lfljvenaura@gmail.com>]

Golden ratio discovered in quantum world: Hidden symmetry observed for the
first time in solid state matter
Date: January 7, 2010
Source: Helmholtz Association of German Research Centres
Summary: Researchers have for the first time observed a nanoscale symmetry
hidden in solid state matter. They have measured the signatures of a
symmetry showing the same attributes as the golden ratio famous from art
and architecture.

http://www.sciencedaily.com/releases/2010/01/100107143909.htm

The magnetic field is used to tune the chains of spins to a quantum
critical state. The resonant modes (“notes”) are detected by scattering
neutrons. These scatter with the characteristic frequencies of the spin
chains.
Credit: Image courtesy of Helmholtz Association of German Research Centres

Researchers from the Helmholtz-Zentrum Berlin für Materialien und Energie
(HZB), in cooperation with colleagues from Oxford and Bristol Universities,
as well as the Rutherford Appleton Laboratory, UK, have for the first time
observed a nanoscale symmetry hidden in solid state matter. They have
measured the signatures of a symmetry showing the same attributes as the
golden ratio famous from art and architecture.

The research team is publishing these findings in the Jan. 8, 2010 issue of
the journal Science.

On the atomic scale particles do not behave as we know it in the
macro-atomic world. New properties emerge which are the result of an effect
known as the Heisenberg's Uncertainty Principle. In order to study these
nanoscale quantum effects the researchers have focused on the magnetic
material cobalt niobate. It consists of linked magnetic atoms, which form
chains just like a very thin bar magnet, but only one atom wide and are a
useful model for describing ferromagnetism on the nanoscale in solid state
matter.

When applying a magnetic field at right angles to an aligned spin the
magnetic chain will transform into a new state called quantum critical,
which can be thought of as a quantum version of a fractal pattern. Prof.
Alan Tennant, the leader of the Berlin group, explains "The system reaches
a quantum uncertain -- or a Schrödinger cat state. This is what we did in
our experiments with cobalt niobate. We have tuned the system exactly in
order to turn it quantum critical."

By tuning the system and artificially introducing more quantum uncertainty
the researchers observed that the chain of atoms acts like a nanoscale
guitar string. Dr. Radu Coldea from Oxford University, who is the principal
author of the paper and drove the international project from its inception
a decade ago until the present, explains: "Here the tension comes from the
interaction between spins causing them to magnetically resonate. For these
interactions we found a series (scale) of resonant notes: The first two
notes show a perfect relationship with each other. Their frequencies
(pitch) are in the ratio of 1.618…, which is the golden ratio famous from
art and architecture." Radu Coldea is convinced that this is no
coincidence. "It reflects a beautiful property of the quantum system -- a
hidden symmetry. Actually quite a special one called E8 by mathematicians,
and this is its first observation in a material," he explains.

The observed resonant states in cobalt niobate are a dramatic laboratory
illustration of the way in which mathematical theories developed for
particle physics may find application in nanoscale science and ultimately
in future technology. Prof. Tennant remarks on the perfect harmony found in
quantum uncertainty instead of disorder. "Such discoveries are leading
physicists to speculate that the quantum, atomic scale world may have its
own underlying order. Similar surprises may await researchers in other
materials in the quantum critical state."

The researchers achieved these results by using a special probe -- neutron
scattering. It allows physicists to see the actual atomic scale vibrations
of a system. Dr. Elisa Wheeler, who has worked at both Oxford University
and Berlin on the project, explains "using neutron scattering gives us
unrivalled insight into how different the quantum world can be from the
every day."

However, "the conflicting difficulties of a highly complex neutron
experiment integrated with low temperature equipment and precision high
field apparatus make this a very challenging undertaking indeed." In order
to achieve success "in such challenging experiments under extreme
conditions" the HZB in Berlin has brought together world leaders in this
field. By combining the special expertise in Berlin whilst taking advantage
of the pulsed neutrons at ISIS, near Oxford, permitted a perfect
combination of measurements to be made.

Story Source:

The above post is reprinted from materials provided by Helmholtz
Association of German Research Centres. Note: Materials may be edited for
content and length.

Journal Reference:

R. Coldea, D. A. Tennant, E. M. Wheeler, E. Wawrzynska, D.
Prabhakaran, M. Telling, K. Habicht, P. Smeibidl, K. Kiefer. Quantum
Criticality in an Ising Chain: Experimental Evidence for Emergent E8
Symmetry. Science, Jan. 8, 2010

<>

http://www.eurekalert.org/pub_releases/2010-01/haog-grd010510.php
Public Release: 7-Jan-2010
Golden ratio discovered in a quantum world

Hidden symmetry observed for the first time in solid state matter

Helmholtz Association

This release is available in German.

Researchers from the Helmholtz-Zentrum Berlin für Materialien und Energie
(HZB), in cooperation with colleagues from Oxford and Bristol Universities,
as well as the Rutherford Appleton Laboratory, UK, have for the first time
observed a nanoscale symmetry hidden in solid state matter. They have
measured the signatures of a symmetry showing the same attributes as the
golden ratio famous from art and architecture. The research team is
publishing these findings in Science on the 8. January.

On the atomic scale particles do not behave as we know it in the
macro-atomic world. New properties emerge which are the result of an effect
known as the Heisenberg's Uncertainty Principle. In order to study these
nanoscale quantum effects the researchers have focused on the magnetic
material cobalt niobate. It consists of linked magnetic atoms, which form
chains just like a very thin bar magnet, but only one atom wide and are a
useful model for describing ferromagnetism on the nanoscale in solid state
matter.

When applying a magnetic field at right angles to an aligned spin the
magnetic chain will transform into a new state called quantum critical,
which can be thought of as a quantum version of a fractal pattern. Prof.
Alan Tennant, the leader of the Berlin group, explains "The system reaches
a quantum uncertain - or a Schrödinger cat state. This is what we did in
our experiments with cobalt niobate. We have tuned the system exactly in
order to turn it quantum critical."

By tuning the system and artificially introducing more quantum uncertainty
the researchers observed that the chain of atoms acts like a nanoscale
guitar string. Dr. Radu Coldea from Oxford University, who is the principal
author of the paper and drove the international project from its inception
a decade ago until the present, explains: "Here the tension comes from the
interaction between spins causing them to magnetically resonate. For these
interactions we found a series (scale) of resonant notes: The first two
notes show a perfect relationship with each other. Their frequencies
(pitch) are in the ratio of 1.618..., which is the golden ratio famous from
art and architecture." Radu Coldea is convinced that this is no
coincidence. "It reflects a beautiful property of the quantum system - a
hidden symmetry. Actually quite a special one called E8 by mathematicians,
and this is its first observation in a material", he explains.

The observed resonant states in cobalt niobate are a dramatic laboratory
illustration of the way in which mathematical theories developed for
particle physics may find application in nanoscale science and ultimately
in future technology. Prof. Tennant remarks on the perfect harmony found in
quantum uncertainty instead of disorder. "Such discoveries are leading
physicists to speculate that the quantum, atomic scale world may have its
own underlying order. Similar surprises may await researchers in other
materials in the quantum critical state."

The researchers achieved these results by using a special probe - neutron
scattering. It allows physicists to see the actual atomic scale vibrations
of a system. Dr. Elisa Wheeler, who has worked at both Oxford University
and Berlin on the project, explains "using neutron scattering gives us
unrivalled insight into how different the quantum world can be from the
every day". However, "the conflicting difficulties of a highly complex
neutron experiment integrated with low temperature equipment and precision
high field apparatus make this a very challenging undertaking indeed." In
order to achieve success "in such challenging experiments under extreme
conditions" the HZB in Berlin has brought together world leaders in this
field. By combining the special expertise in Berlin whilst taking advantage
of the pulsed neutrons at ISIS, near Oxford, permitted a perfect
combination of measurements to be made.

###


*Article in Science, *DOI: RE1180085/JEC/PHYSICS *Quantum Criticality in an
Ising Chain: Experimental Evidence for Emergent E8 Symmetry*
R. Coldea, D. A. Tennant, E. M. Wheeler, E. Wawrzynska, D. Prabhakaran, M.
Telling, K. Habicht, P. Smeibidl, K. Kiefer

press contact: Dr. Ina Helms, ina.helms@helmholtz-berlin.de

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news releases posted to EurekAlert! by contributing institutions or for the
use of any information through the EurekAlert system.




-- 
Lawrence F. London
lfljvenaura@gmail.com
https://sites.google.com/site/avantgeared/