Mark Lumsden - Academia.edu (original) (raw)
Papers by Mark Lumsden
Christian Balz, ∗ Paula Lampen-Kelley, 3 Arnab Banerjee, Jiaqiang Yan, Zhilun Lu, Xinzhe Hu, Swap... more Christian Balz, ∗ Paula Lampen-Kelley, 3 Arnab Banerjee, Jiaqiang Yan, Zhilun Lu, Xinzhe Hu, Swapnil M. Yadav, Yasu Takano, Yaohua Liu, David A. Tennant, Mark D. Lumsden, David Mandrus, 3 and Stephen E. Nagler Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany Department of Physics, University of Florida, Gainesville, Florida 32611, USA (Dated: March 15, 2019)
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Inelastic neutron scattering was used to probe the spin dynamics of the long-range magnetic struc... more Inelastic neutron scattering was used to probe the spin dynamics of the long-range magnetic structure of single crystal FeGe2. An unusual checkerboard-shaped anomaly located far from the magnetic satellite peaks of the incommensurate order was found in the magnetic dynamical structure factor. Using expanded ranges of wave-vector and energy transfer, we are able to develop a new model Hamiltonian that includes a heretofore unconsidered intraplane next-nearest neighbor interaction. The checkerboard-shaped anomaly is attributed to the near-perfect magnetic frustration in FeGe2, which also facilitates the emergence of unexpected two-dimension magnetic order in the system.
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arXiv: Strongly Correlated Electrons, 2006
The competition between the tendency of magnetic moments to order at low temperatures, and the te... more The competition between the tendency of magnetic moments to order at low temperatures, and the tendency of conduction electrons to shield these moments, can result in a phase transition that takes place at zero Kelvin, the quantum critical point (QCP). So far, the ground state of these types of systems has remained unresolved. We present neutron scattering experiments that show that the ground state of a sample representative of a class of QCP-systems is determined by the residual interactions between the conduction electrons, resulting in a state with incommensurate intermediate-range order. However, long-range order is thwarted by quantum fluctuations that locally destroy magnetic moments, leaving the system with too few moments to achieve long-range order.
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Journal of Physics: Condensed Matter, 2018
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Proceedings of the National Academy of Sciences, 2015
Significance Liquid polymorphism and liquid–liquid phase transformations are remarkable phenomena... more Significance Liquid polymorphism and liquid–liquid phase transformations are remarkable phenomena of great fundamental and practical interest, as is unconventional superconductivity. Yet, despite being intensely studied, they still remain enigmatic. Our results not only provide a rare experimental example of liquid polymorphism, which occurs in the spin system of an iron chalcogenide superconductor, but also establish its unexpected connection with the onset of unconventional superconductivity.
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Physical Review B, 2007
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Physical Review Letters, 2001
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Physical Review Letters, 2012
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Physical Review Letters, 2008
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Physical Review Letters, 2002
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Physical Review Letters, 2014
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Physical Review Letters, 2008
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Physical Review B, 2011
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Physical Review B, 2010
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Physical Review B, 2008
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Physical Review B, 2006
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Physical Review B, 2012
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Physical Review B, 2011
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Physical Review B, 2012
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Physical Review B, 2012
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Christian Balz, ∗ Paula Lampen-Kelley, 3 Arnab Banerjee, Jiaqiang Yan, Zhilun Lu, Xinzhe Hu, Swap... more Christian Balz, ∗ Paula Lampen-Kelley, 3 Arnab Banerjee, Jiaqiang Yan, Zhilun Lu, Xinzhe Hu, Swapnil M. Yadav, Yasu Takano, Yaohua Liu, David A. Tennant, Mark D. Lumsden, David Mandrus, 3 and Stephen E. Nagler Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany Department of Physics, University of Florida, Gainesville, Florida 32611, USA (Dated: March 15, 2019)
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Inelastic neutron scattering was used to probe the spin dynamics of the long-range magnetic struc... more Inelastic neutron scattering was used to probe the spin dynamics of the long-range magnetic structure of single crystal FeGe2. An unusual checkerboard-shaped anomaly located far from the magnetic satellite peaks of the incommensurate order was found in the magnetic dynamical structure factor. Using expanded ranges of wave-vector and energy transfer, we are able to develop a new model Hamiltonian that includes a heretofore unconsidered intraplane next-nearest neighbor interaction. The checkerboard-shaped anomaly is attributed to the near-perfect magnetic frustration in FeGe2, which also facilitates the emergence of unexpected two-dimension magnetic order in the system.
Bookmarks Related papers MentionsView impact
arXiv: Strongly Correlated Electrons, 2006
The competition between the tendency of magnetic moments to order at low temperatures, and the te... more The competition between the tendency of magnetic moments to order at low temperatures, and the tendency of conduction electrons to shield these moments, can result in a phase transition that takes place at zero Kelvin, the quantum critical point (QCP). So far, the ground state of these types of systems has remained unresolved. We present neutron scattering experiments that show that the ground state of a sample representative of a class of QCP-systems is determined by the residual interactions between the conduction electrons, resulting in a state with incommensurate intermediate-range order. However, long-range order is thwarted by quantum fluctuations that locally destroy magnetic moments, leaving the system with too few moments to achieve long-range order.
Bookmarks Related papers MentionsView impact
Journal of Physics: Condensed Matter, 2018
Bookmarks Related papers MentionsView impact
Proceedings of the National Academy of Sciences, 2015
Significance Liquid polymorphism and liquid–liquid phase transformations are remarkable phenomena... more Significance Liquid polymorphism and liquid–liquid phase transformations are remarkable phenomena of great fundamental and practical interest, as is unconventional superconductivity. Yet, despite being intensely studied, they still remain enigmatic. Our results not only provide a rare experimental example of liquid polymorphism, which occurs in the spin system of an iron chalcogenide superconductor, but also establish its unexpected connection with the onset of unconventional superconductivity.
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Physical Review B, 2007
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Physical Review Letters, 2001
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Physical Review Letters, 2012
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Physical Review Letters, 2008
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Physical Review Letters, 2002
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Physical Review Letters, 2014
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Physical Review Letters, 2008
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Physical Review B, 2011
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Physical Review B, 2010
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Physical Review B, 2008
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Physical Review B, 2006
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Physical Review B, 2012
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Physical Review B, 2011
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Physical Review B, 2012
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Physical Review B, 2012
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