title: Evolution of the magnetic structure in CeCu(5.5)Au(0.5) under pressure towards quantum criticality.
abstract: In the prototypical heavy-fermion system CeCu(6-x)Au(x), a magnetic quantum critical point can be tuned by Au concentration x, hydrostatic pressure p, or magnetic field B. A striking equivalence of the tuning behavior with x or p had been found with respect to thermodynamic and transport properties. By means of elastic neutron scattering on single crystalline CeCu(5.5)Au(0.5), we demonstrate this x-p equivalence on a microscopic level by showing that the magnetic ordering wave vector q(m) can be tuned accordingly. At ambient pressure,CeCu(5.5)Au(0.5) orders at q(m)≈(0.59 0 0). Upon applying p=4.1 kbar, q(m)≈(0.61 0 0.21) is found corresponding to CeCu(5.6)Au(0.4) at ambient pressure. The transition seems to occur in a first-order fashion and to be governed by slight changes in the nesting properties of the Fermi surface.
authors.affiliation: Institut für Festkörperphysik, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hamann
authors.forename: O
authors.initials: O
authors.lastname: Stockert
authors.forename: V
authors.initials: V
authors.lastname: Fritsch
authors.forename: K
authors.initials: K
authors.lastname: Grube
authors.forename: A
authors.initials: A
authors.lastname: Schneidewind
authors.forename: H v
authors.initials: Hv
authors.lastname: Löhneysen