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Broussard LJ, Barrow JL, DeBeer-Schmitt L, Dennis T, Fitzsimmons MR, Frost MJ, Gilbert CE, Gonzalez FM, Heilbronn L, Iverson EB, Johnston A, Kamyshkov Y, Kline M, Lewiz P, Matteson C, Ternullo J, Varriano L, Vavra S. Experimental Search for Neutron to Mirror Neutron Oscillations as an Explanation of the Neutron Lifetime Anomaly. Phys Rev Lett 2022; 128:212503. [PMID: 35687456 DOI: 10.1103/physrevlett.128.212503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/25/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
An unexplained >4σ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions of neutrons n into mirror neutrons n^{'}, part of a dark mirror sector, can increase the apparent neutron lifetime by 1% via a small mass splitting Δm between n and n^{'} inside the 4.6 T magnetic field of the National Institute of Standards and Technology Beam Lifetime experiment. A search for neutron conversions in a 6.6 T magnetic field was performed at the Spallation Neutron Source which excludes this explanation for the neutron lifetime discrepancy.
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Affiliation(s)
- L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J L Barrow
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | | | - T Dennis
- Department of Physics and Astronomy, East Tennessee State University, Johnson City, Tennessee 37614, USA
| | - M R Fitzsimmons
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M J Frost
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C E Gilbert
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - F M Gonzalez
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Heilbronn
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - E B Iverson
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Johnston
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Y Kamyshkov
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M Kline
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - P Lewiz
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C Matteson
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - J Ternullo
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - L Varriano
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - S Vavra
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
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2
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Bordács S, Farkas DG, White JS, Cubitt R, DeBeer-Schmitt L, Ito T, Kézsmárki I. Magnetic Field Control of Cycloidal Domains and Electric Polarization in Multiferroic BiFeO_{3}. Phys Rev Lett 2018; 120:147203. [PMID: 29694132 DOI: 10.1103/physrevlett.120.147203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Indexed: 05/05/2023]
Abstract
The magnetic field induced rearrangement of the cycloidal spin structure in ferroelectric monodomain single crystals of the room-temperature multiferroic BiFeO_{3} is studied using small-angle neutron scattering. The cycloid propagation vectors are observed to rotate when magnetic fields applied perpendicular to the rhombohedral (polar) axis exceed a pinning threshold value of ∼5 T. In light of these experimental results, a phenomenological model is proposed that captures the rearrangement of the cycloidal domains, and we revisit the microscopic origin of the magnetoelectric effect. A new coupling between the magnetic anisotropy and the polarization is proposed that explains the recently discovered magnetoelectric polarization perpendicular to the rhombohedral axis.
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Affiliation(s)
- S Bordács
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Magneto-optical Spectroscopy Research Group, 1111 Budapest, Hungary
- Hungarian Academy of Sciences, Premium Postdoctor Program, 1051 Budapest, Hungary
| | - D G Farkas
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Magneto-optical Spectroscopy Research Group, 1111 Budapest, Hungary
| | - J S White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
| | - R Cubitt
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - L DeBeer-Schmitt
- Large Scale Structure Group, Neutron Science Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Ito
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8562 Ibaraki, Japan
| | - I Kézsmárki
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Magneto-optical Spectroscopy Research Group, 1111 Budapest, Hungary
- Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
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3
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Fuhrman WT, Leiner J, Nikolić P, Granroth GE, Stone MB, Lumsden MD, DeBeer-Schmitt L, Alekseev PA, Mignot JM, Koohpayeh SM, Cottingham P, Phelan WA, Schoop L, McQueen TM, Broholm C. Interaction driven subgap spin exciton in the Kondo insulator SmB6. Phys Rev Lett 2015; 114:036401. [PMID: 25659009 DOI: 10.1103/physrevlett.114.036401] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Indexed: 06/04/2023]
Abstract
Using inelastic neutron scattering, we map a 14 meV coherent resonant mode in the topological Kondo insulator SmB6 and describe its relation to the low energy insulating band structure. The resonant intensity is confined to the X and R high symmetry points, repeating outside the first Brillouin zone and dispersing less than 2 meV, with a 5d-like magnetic form factor. We present a slave-boson treatment of the Anderson Hamiltonian with a third neighbor dominated hybridized band structure. This approach produces a spin exciton below the charge gap with features that are consistent with the observed neutron scattering. We find that maxima in the wave vector dependence of the inelastic neutron scattering indicate band inversion.
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Affiliation(s)
- W T Fuhrman
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - J Leiner
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - P Nikolić
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA
| | - G E Granroth
- Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M B Stone
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M D Lumsden
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L DeBeer-Schmitt
- Instrument Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - P A Alekseev
- National Research Centre "Kurchatov Institute," 123182 Moscow, Russia and National Research Nuclear University "MEPhI," 115409 Moscow, Russia
| | - J-M Mignot
- Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif sur Yvette, France
| | - S M Koohpayeh
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - P Cottingham
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - W Adam Phelan
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - L Schoop
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, Princeton University, Princeton, New Jersey 08540, USA
| | - T M McQueen
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - C Broholm
- Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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4
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Stone MB, Niedziela JL, Abernathy DL, DeBeer-Schmitt L, Ehlers G, Garlea O, Granroth GE, Graves-Brook M, Kolesnikov AI, Podlesnyak A, Winn B. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source. Rev Sci Instrum 2014; 85:045113. [PMID: 24784665 DOI: 10.1063/1.4870050] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.
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Affiliation(s)
- M B Stone
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J L Niedziela
- Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D L Abernathy
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L DeBeer-Schmitt
- Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G Ehlers
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Garlea
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G E Granroth
- Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M Graves-Brook
- Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A I Kolesnikov
- Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Podlesnyak
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Winn
- Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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5
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Rastovski C, Schlesinger KJ, Gannon WJ, Dewhurst CD, DeBeer-Schmitt L, Zhigadlo ND, Karpinski J, Eskildsen MR. Persistence of metastable vortex lattice domains in MgB2 in the presence of vortex motion. Phys Rev Lett 2013; 111:107002. [PMID: 25166696 DOI: 10.1103/physrevlett.111.107002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 08/06/2013] [Indexed: 06/03/2023]
Abstract
Recently, extensive vortex lattice metastability was reported in MgB2 in connection with a second-order rotational phase transition. However, the mechanism responsible for these well-ordered metastable vortex lattice phases is not well understood. Using small-angle neutron scattering, we studied the vortex lattice in MgB2 as it was driven from a metastable to the ground state through a series of small changes in the applied magnetic field. Our results show that metastable vortex lattice domains persist in the presence of substantial vortex motion and directly demonstrate that the metastability is not due to vortex pinning. Instead, we propose that it is due to the jamming of counterrotated vortex lattice domains which prevents a rotation to the ground state orientation.
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Affiliation(s)
- C Rastovski
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - K J Schlesinger
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - W J Gannon
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60660, USA
| | - C D Dewhurst
- Institut Laue-Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France
| | | | - N D Zhigadlo
- Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - J Karpinski
- Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland and Institute of Condensed Matter Physics, EPFL, CH-1015 Lausanne, Switzerland
| | - M R Eskildsen
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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6
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Das P, Rastovski C, O'Brien TR, Schlesinger KJ, Dewhurst CD, DeBeer-Schmitt L, Zhigadlo ND, Karpinski J, Eskildsen MR. Observation of well-ordered metastable vortex lattice phases in superconducting MgB2 using small-angle neutron scattering. Phys Rev Lett 2012; 108:167001. [PMID: 22680750 DOI: 10.1103/physrevlett.108.167001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Indexed: 06/01/2023]
Abstract
The vortex lattice (VL) symmetry and orientation in clean type-II superconductors depends sensitively on the host material anisotropy, vortex density and temperature, frequently leading to rich phase diagrams. Typically, a well-ordered VL is taken to imply a ground-state configuration for the vortex-vortex interaction. Using neutron scattering we studied the VL in MgB(2) for a number of field-temperature histories, discovering an unprecedented degree of metastability in connection with a known, second-order rotation transition. This allows, for the first time, structural studies of a well-ordered, nonequilibrium VL. While the mechanism responsible for the longevity of the metastable states is not resolved, we speculate it is due to a jamming of VL domains, preventing a rotation to the ground-state orientation.
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Affiliation(s)
- P Das
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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7
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DeBeer-Schmitt L, Eskildsen MR, Ichioka M, Machida K, Jenkins N, Dewhurst CD, Abrahamsen AB, Bud'ko SL, Canfield PC. Pauli paramagnetic effects on vortices in superconducting TmNi2B2C. Phys Rev Lett 2007; 99:167001. [PMID: 17995281 DOI: 10.1103/physrevlett.99.167001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Indexed: 05/25/2023]
Abstract
The magnetic field distribution around the vortices in TmNi2B2C in the paramagnetic phase was studied experimentally as well as theoretically. The vortex form factor, measured by small-angle neutron scattering, is found to be field independent up to 0.6Hc2 followed by a sharp decrease at higher fields. The data are fitted well by solutions to the Eilenberger equations when paramagnetic effects due to the exchange interaction with the localized 4f Tm moments are included. The induced paramagnetic moments around the vortex cores act to maintain the field contrast probed by the form factor.
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Affiliation(s)
- L DeBeer-Schmitt
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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8
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DeBeer-Schmitt L, Dewhurst CD, Hoogenboom BW, Petrovic C, Eskildsen MR. Field dependent coherence length in the superclean, high-kappa superconductor CeCoIn5. Phys Rev Lett 2006; 97:127001. [PMID: 17025991 DOI: 10.1103/physrevlett.97.127001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Indexed: 05/12/2023]
Abstract
Using small-angle neutron scattering, we have studied the flux-line lattice (FLL) in the superclean, high-kappa superconductor CeCoIn5. The FLL undergoes a first-order symmetry and reorientation transition at approximately 0.55 T at 50 mK. In addition, the FLL form factor in this material is found to be independent of the applied magnetic field, in striking contrast to the exponential decrease usually observed in superconductors. This result is consistent with a strongly field-dependent coherence length, proportional to the vortex separation.
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Affiliation(s)
- L DeBeer-Schmitt
- Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA
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