Quantum Phase Transition of a Magnet in a Spin Bath
Quantum Phase Transition of a Magnet in a Spin Bath
The excitation spectrum of a model magnetic system, LiHoF4, was studied with the use of neutron spectroscopy as the system was tuned to its quantum critical point by an applied magnetic field. The electronic mode softening expected for a quantum phase transition was forestalled by hyperfine coupling to the nuclear …