title: Singular field response and singular screening of vacancies in antiferromagnets.
abstract: For isolated vacancies in ordered local-moment antiferromagnets we show that the magnetic-field linear-response limit is generically singular: The magnetic moment associated with a vacancy in zero field is different from that in a finite field h in the limit h→0(+). The origin is a universal and singular screening cloud, which moreover leads to perfect screening as h→0(+) for magnets which display spin-flop bulk states in the weak-field limit.
authors.affiliation: Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wollny
authors.forename: Eric C
authors.initials: EC
authors.lastname: Andrade
authors.forename: Matthias
authors.initials: M
authors.lastname: Vojta