title: A magnetically shielded room with ultra low residual field and gradient.
abstract: A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Altarev
authors.affiliation: Jülich Center for Neutron Science, Lichtenbergstrasse 1, D-85748 Garching, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Babcock
authors.affiliation: Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: D
authors.initials: D
authors.lastname: Beck
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Burghoff
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Chesnevskaya
authors.affiliation: Physics Department, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: T
authors.initials: T
authors.lastname: Chupp
authors.affiliation: Physics Department, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: S
authors.initials: S
authors.lastname: Degenkolb
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Fan
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany, and Fierlinger Magnetics GmbH, D-85748 Garching, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Fierlinger
authors.affiliation: Forschungneutronenquelle Heinz Meier-Leibnitz, D-85748 Garching, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Frei
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Gutsmiedl
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Knappe-Grüneberg
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kuchler
authors.affiliation: Forschungneutronenquelle Heinz Meier-Leibnitz, D-85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Lauer
authors.affiliation: Forschungneutronenquelle Heinz Meier-Leibnitz, D-85748 Garching, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Link
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Lins
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Marino
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: J
authors.initials: J
authors.lastname: McAndrew
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Niessen
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Paul
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Petzoldt
authors.affiliation: IMEDCO AG, CH-4614 Hägendorf, Switzerland.
authors.forename: U
authors.initials: U
authors.lastname: Schläpfer
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Schnabel
authors.affiliation: Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Singh
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Stoepler
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Stuiber
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Sturm
authors.affiliation: Physikdepartment, Technische Universität München, D-85748 Garching, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Taubenheim
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Trahms
authors.affiliation: Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Voigt
authors.affiliation: Forschungneutronenquelle Heinz Meier-Leibnitz, D-85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Zechlau