title: Magnetic-field-induced soft-mode quantum phase transition in the high-temperature superconductor La1.855Sr0.145CuO4: an inelastic neutron-scattering study.
abstract: Inelastic neutron-scattering experiments on the high-temperature superconductor La1.855Sr0.145CuO4 reveal a magnetic excitation gap Delta that decreases continuously upon application of a magnetic field perpendicular to the CuO2 planes. The gap vanishes at the critical field required to induce long-range incommensurate antiferromagnetic order, providing compelling evidence for a field-induced soft-mode driven quantum phase transition.
authors.affiliation: Laboratory for Neutron Scattering, ETH Zurich and PSI Villigen, CH-5232 Villigen PSI, Switzerland. jchang@physique.usherbrooke.ca
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.forename: N B
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authors.lastname: Christensen
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authors.lastname: Niedermayer
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authors.lastname: Lefmann
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authors.lastname: Boehm
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authors.lastname: Mottl
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authors.lastname: Pailhés
authors.forename: N
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authors.lastname: Momono
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authors.lastname: Ido
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authors.lastname: Mesot