Spin ice under pressure: symmetry enhancement and infinite order multicriticality.
We study the low-temperature behavior of spin ice when uniaxial pressure induces a tetragonal distortion. There is a phase transition between a Coulomb liquid and a fully magnetized phase. Unusually, it combines features of discontinuous and continuous transitions: the order parameter exhibits a jump, but this is accompanied by a divergent susceptibility and vanishing domain wall tension. All these aspects can be understood as a consequence of an emergent SU(2) symmetry at the critical point. We map out a possible experimental realization.
Jaubert
L D C
LD
Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany.
Chalker
J T
JT
Holdsworth
P C W
PC
Moessner
R
R