title: Pressure-induced inhomogeneous chiral-spin ground state in FeGe.
abstract: (57)Fe nuclear forward scattering on the chiral magnet FeGe reveals an extremely large precursor phase region above the helimagnetic ordering temperature T(C)(p) and beyond the pressure-induced quantum phase transition at 19 GPa. The decrease of the magnetic hyperfine field ⟨B(hf)⟩ with pressure is accompanied by a large increase of the width of the distribution of ⟨B(hf)⟩, indicating a strong quasistatic inhomogeneity of the magnetic states in the precursor region. Hyperfine fields of the order of 4 T (equivalent to a magnetic moment μ(Fe)≈0.4μ(B)) persist up to 28.5 GPa. No signatures of magnetic order have been found at about 31 GPa. The results, supported by ab initio calculations, suggest that chiral magnetic precursor phenomena, such as an inhomogeneous chiral-spin state, are vastly enlarged due to increasing spin fluctuations as FeGe is tuned to its quantum phase transition.
authors.affiliation: Istituto di Struttura della Materia, ISM-CNR, I-34149 Trieste, Italy and ALBA Synchrotron Light Source, E-08290 Cerdanyola del Vallés, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Barla
authors.affiliation: Diamond Light Source Ltd, Chilton, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Wilhelm
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, D-50937 Köln, Germany.
authors.forename: M K
authors.initials: MK
authors.lastname: Forthaus
authors.affiliation: European Synchrotron Radiation Facility, F-38043 Grenoble, France.
authors.forename: C
authors.initials: C
authors.lastname: Strohm
authors.affiliation: European Synchrotron Radiation Facility, F-38043 Grenoble, France.
authors.forename: R
authors.initials: R
authors.lastname: Rüffer
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: IFW Dresden, Postfach 270116, D-01171 Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Koepernik
authors.affiliation: IFW Dresden, Postfach 270116, D-01171 Dresden, Germany.
authors.forename: U K
authors.initials: UK
authors.lastname: Rössler
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, D-50937 Köln, Germany.
authors.forename: M M
authors.initials: MM
authors.lastname: Abd-Elmeguid