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 spins. We found that interactions with the nuclear spin bath controlled the length scale over which the excitations could be entangled. This generic result places a limit on our ability to observe intrinsic electronic quantum criticality.

Published in:
Science, 308, 5720, 389-392
ETH, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Riso Natl Lab, DK-4000 Roskilde, Denmark. Niels Bohr Inst fAPG, Orsted Lab, DK-2100 Copenhagen, Denmark. Univ Coll London, London Ctr Nanotechnol, London WC1E 6BT, England. Univ Coll London, Dept Phys & Astron, London WC1E 6BT, England. Rutherford Appleton Lab, ISIS, Didcot OX11 0QX, Oxon, England. Ronnow, HM, ETH, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. henrik.ronnow@psi.ch

 Record created 2007-01-24, last modified 2018-03-17

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