Quantum Criticality in an Ising Chain: Experimental Evidence for Emergent E 8 Symmetry
University of Oxford · Helmholtz-Zentrum Berlin für Materialien und Energie · +2 more institutions
Abstract
Quantum phase transitions take place between distinct phases of matter at zero temperature. Near the transition point, exotic quantum symmetries can emerge that govern the excitation spectrum of the system. A symmetry described by the E8 Lie group with a spectrum of eight particles was long predicted to appear near the critical point of an Ising chain. We realize this system experimentally by using strong transverse magnetic fields to tune the quasi-one-dimensional Ising ferromagnet CoNb2O6 (cobalt niobate) through its critical point. Spin excitations are observed to change character from pairs of kinks in the ordered phase to spin-flips in the paramagnetic phase. Just below the critical field, the spin…
Citation impact
- FWCI
- 35.22
- Percentile
- 100%
- References
- 22
Authors
9Topics & keywords
- Ising model
- Physics
- Quantum critical point
- Condensed matter physics
- Critical point (mathematics)
- Quantum phase transition
- Quantum
- Spin (aerodynamics)