Observation of the Kibble-Zurek scaling law for defect formation in ion crystals.
Traversal of a symmetry-breaking phase transition at finite rates can lead to causally separated regions with incompatible symmetries and the formation of defects at their boundaries, which has a crucial role in quantum and statistical mechanics, cosmology and condensed matter physics. This mechanism is conjectured to follow universal scaling laws prescribed by the Kibble-Zurek mechanism. Here we determine the scaling law for defect formation in a crystal of 16 laser-cooled trapped ions, which are conducive to the precise control of structural phases and the detection of defects. The experiment reveals an exponential scaling of defect formation γ(β), where γ is the rate of traversal of the critical point and β=2.68±0.06. This supports the prediction of β=8/3≈2.67 for finite inhomogeneous systems. Our result demonstrates that the scaling laws also apply in the mesoscopic regime and emphasizes the potential for further tests of non-equilibrium thermodynamics with ion crystals.
QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany. ulmst@uni-mainz.de
S
S
Ulm
J
J
Roßnagel
G
G
Jacob
C
C
Degünther
S T
ST
Dawkins
U G
UG
Poschinger
R
R
Nigmatullin
A
A
Retzker
M B
MB
Plenio
F
F
Schmidt-Kaler
K
K
Singer