7/21/2019 Golden Ratio Discovered in Quantum World

1/3

Golden ratio discovered in quantum world:Hidden symmetry observed for the first timein solid state matter

Date: January 7, 2010

Source: Helmholtz Association of German Research Centres

he ma!netic fiel" is use" to tune the chains of s#ins to a $uantum critical state% he resonant mo"es

&'notes() are "etecte" *y scatterin! neutrons% hese scatter +ith the characteristic fre$uencies of the

s#in chains%

Researchers from the Helmholtz-entrum .erlin f/r

aterialien un" ner!ie &H-.), in coo#eration +ith collea!ues from 3for" an" .ristol 4ni5ersities,

as +ell as the Rutherfor" A##leton 6a*oratory, 4, ha5e for the first time o*ser5e" a nanoscale

symmetry hi""en in soli" state matter% hey ha5e measure" the si!natures of a symmetry sho+in! the

same attri*utes as the !ol"en ratio famous from art an" architecture%

he research team is #u*lishin! these fin"in!s in the Jan% 8, 2010 issue of the 9ournal Science%

n the atomic scale #articles "o not *eha5e as +e no+ it in the macroatomic +orl"% ;e+ #ro#erties

emer!e +hich are the result of an effect no+n as the Heisen*er!n or"er to

stu"y these nanoscale $uantum effects the researchers ha5e focuse" on the ma!netic material co*alt

Credit: Image courtesy of Helmholtz

ssociation of German Research Centres

7/21/2019 Golden Ratio Discovered in Quantum World

2/3

nio*ate% >t consists of line" ma!netic atoms, +hich form chains 9ust lie a 5ery thin *ar ma!net, *ut

only one atom +i"e an" are a useful mo"el for "escri*in! ferroma!netism on the nanoscale in soli"

state matter%

?hen a##lyin! a ma!netic fiel" at ri!ht an!les to an ali!ne" s#in the ma!netic chain +ill transform

into a ne+ state calle" $uantum critical, +hich can *e thou!ht of as a $uantum 5ersion of a fractal

#attern% =rof% Alan ennant, the lea"er of the .erlin !rou#, e3#lains @he system reaches a $uantumuncertain or a Schr"in!er cat state% his is +hat +e "i" in our e3#eriments +ith co*alt nio*ate% ?e

ha5e tune" the system e3actly in or"er to turn it $uantum critical%@

.y tunin! the system an" artificially intro"ucin! more $uantum uncertainty the researchers o*ser5e"

that the chain of atoms acts lie a nanoscale !uitar strin!% Dr% Ra"u Col"ea from 3for" 4ni5ersity,

+ho is the #rinci#al author of the #a#er an" "ro5e the international #ro9ect from its ince#tion a "eca"e

a!o until the #resent, e3#lains: @Here the tension comes from the interaction *et+een s#ins causin!

them to ma!netically resonate% Bor these interactions +e foun" a series &scale) of resonant notes: he

first t+o notes sho+ a #erfect relationshi# +ith each other% heir fre$uencies itch) are in the ratio of

1%18, +hich is the !ol"en ratio famous from art an" architecture%@ Ra"u Col"ea is con5ince" that

this is no coinci"ence% @>t reflects a *eautiful #ro#erty of the $uantum system a hi""en symmetry%

Actually $uite a s#ecial one calle" 8 *y mathematicians, an" this is its first o*ser5ation in a material,@

he e3#lains%

he o*ser5e" resonant states in co*alt nio*ate are a "ramatic la*oratory illustration of the +ay in +hich

mathematical theories "e5elo#e" for #article #hysics may fin" a##lication in nanoscale science an"

ultimately in future technolo!y% =rof% ennant remars on the #erfect harmony foun" in $uantum

uncertainty instea" of "isor"er% @Such "isco5eries are lea"in! #hysicists to s#eculate that the $uantum,

atomic scale +orl" may ha5e its o+n un"erlyin! or"er% Similar sur#rises may a+ait researchers in other

materials in the $uantum critical state%@

he researchers achie5e" these results *y usin! a s#ecial #ro*e neutron scatterin!% >t allo+s

#hysicists to see the actual atomic scale 5i*rations of a system% Dr% lisa ?heeler, +ho has +ore" at

*oth 3for" 4ni5ersity an" .erlin on the #ro9ect, e3#lains @usin! neutron scatterin! !i5es us unri5alle"

insi!ht into ho+ "ifferent the $uantum +orl" can *e from the e5ery "ay%@

Ho+e5er, @the conflictin! "ifficulties of a hi!hly com#le3 neutron e3#eriment inte!rate" +ith lo+

tem#erature e$ui#ment an" #recision hi!h fiel" a##aratus mae this a 5ery challen!in! un"ertain!

in"ee"%@ >n or"er to achie5e success @in such challen!in! e3#eriments un"er e3treme con"itions@ the

H-. in .erlin has *rou!ht to!ether +orl" lea"ers in this fiel"% .y com*inin! the s#ecial e3#ertise in.erlin +hilst tain! a"5anta!e of the #ulse" neutrons at >S>S, near 3for", #ermitte" a #erfect

com*ination of measurements to *e ma"e%

Story Source:

he a*o5e story is *ase" on materials#ro5i"e" *y Helmholtz Association of German Research

Centres%Note: Materials may be edited for content and length.

http://www.eurekalert.org/pub_releases/2010-01/haog-grd010510.phphttp://www.helmholtz.de/http://www.helmholtz.de/http://www.eurekalert.org/pub_releases/2010-01/haog-grd010510.phphttp://www.helmholtz.de/http://www.helmholtz.de/

7/21/2019 Golden Ratio Discovered in Quantum World

3/3

Journal Reference:

1% R% Col"ea, D% A% ennant, % % ?heeler, % ?a+rzynsa, D% =ra*haaran, % ellin!, %

Ha*icht, =% Smei*i"l, % iefer% Quantum Criticality in an sin! Chain: "#$erimental

"vidence for "mer!ent "% Symmetry% Science, Jan% 8, 2010