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Search Publications by: Joel Helton (Fed)

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Displaying 1 - 16 of 16

Entropy Driven Incommensurate Structures in the Frustrated Kagome Staircase Co3V2O8

February 18, 2024
Author(s)
Joel Helton, Nyrissa Rogado, Robert Cava, Jeffrey Lynn
Co3V2O8 features spin-3/2 moments arrayed on a kagome staircase lattice. A spin density wave with a continuously evolving propagation vector of ⃗k = (0, δ, 0), showing both incommensurate states and multiple commensurate lock-ins, is observed at

Magnetic Transitions in the Topological Magnon Insulator Cu(1,3-bdc)

June 2, 2016
Author(s)
Robin Michael Daub Chisnell, Joel Helton, D. E. Freedman, D. K. Singh, F. Demmel, Chris Stock, D. G. Nocera, Y. S. Lee
Topological magnon insulators are a new class of magnetic materials that posses topologically nontrivial magnon bands. As a result, magnons in these materials display properties analogous to those of electrons in topological insulators. Here, we present

Magnetic Structure of Yb 2 Pt 2 Pb: Ising Moments on the Shastry-Sutherland Lattice

March 22, 2016
Author(s)
W. Miiller, L. S. Wu, M. S. Kim, T. Orvis, J. W. Simonson, M. Gamza, D. M. McNally, C. S. Nelson, G. Ehlers, A. Podlesnyak, Joel Helton, Yang Zhao, Yiming Qiu, John R. Copley, Jeffrey W. Lynn, I. Zaliznyak, M. C. Aronson
Neutron diffraction measurements were carried out on single crystals and powders of Yb 2Pt 2Pb, where Yb moments form planes of orthogonal dimers in the frustrated Shastry-Sutherland Lattice (SSL). Yb 2Pt 2Pb orders antiferromagnetically at T N=2.07 K, and

Topological Magnon Bands in Kagome Lattice Ferromagnet

September 28, 2015
Author(s)
Robin Michael Daub Chisnell, Joel Helton, D. E. Freedman, D. K. Singh, R. I. Bewley, D. G. Nocera, Y. S. Lee
The success of band theory in describing the motion of quantum particles inside solids is a foundational accomplishment in modern physics. Recent excitement has centered on systems for which the bands are topological. Such materials possess novel

Chemical Pressure Tuning of URu 2 Si 2 via Isoelectronic Substitution of Ru with Fe

February 26, 2015
Author(s)
Pinaki Das, N. Kanchanavatee, Joel Helton, K. Huang, R. E. Baumbach, E. D. Bauer, B. D. White, V. W. Burnett, M. B. Maple, Jeffrey W. Lynn, M. Janoschek
We have used specific heat and neutron diffraction measurements on single crystals of UR 2-xFe xSi 2 for Fe concentrations X less than or equal to} 0.7 to establish that chemical substitution of Ru with Fe acts as "chemical pressure" P ch as previously

Polaron-Mediated Spin Correlations in Metallic and Insulating La 1-x A x MnO 3 (A=Ca,Sr, or Ba)

December 3, 2014
Author(s)
Joel Helton, Daniel M Pajerowski, Yiming Qiu, Yang Zhao, Dmitry A. Shulyatev, Yakov M. Mukovskii, Georgii L. Bychkov, Sergei N. Barilo, Jeffrey W. Lynn
Neutron spectroscopy measurements reveal short-range spin correlations near and above the ferromagnetic-paramagnetic phase transition in manganite materials of the form La 10zA xMnO 3, including samples with an insulating ground state as well as colossal

Paramagnetic Spin Correlations in Colossal Magnetoresistive La 0.7 Ca 0.3 MnO 3

April 2, 2012
Author(s)
Joel Helton, Matthew B. Stone, Dmitry A. Shulyatev, Yakov M. Mukovskii, Jeffrey W. Lynn
Neutron spectroscopy measurements reveal dynamic spin correlations throughout the Brillouin zone in the colossal magnetoresistive system La 0.7Ca 0.3MnO 3 at 265 K ({approx}1.03T c). The long-wavelength behavior is consistent with spin diffusion, yet an

Numerical Study of the Thermodynamics of Clinoatacamite

February 1, 2012
Author(s)
Ehsan Khatami, Joel Helton, Marcos Rigol
In this Brief Report, we discuss the use of linked-cluster expansions in solving quantum models that break certain symmetries of the underlying lattice. We sketch the algorithm for the numerical linked-cluster expansions (NLCEs) and show that although some

Evolution of the Commensurate and Incommensurate Magnetic phases of the S{/I= {3/2} Kagome Staircase Co 3 V 2 O 8 in a Applied Field

December 8, 2011
Author(s)
Joel Helton, Georgii L. Bychkov, Sergei N. Barilo, Nyrissa Rogado, Robert J. Cava, Jeffrey W. Lynn
Single crystal neutron diffraction studies have been performed on the S = {3/2} kagome staircase compound Co 3V 2O 8 with a magnetic field applied along the magnetization easy-axis (H || a). Previous zero field measurements [Y. Chen, et al., Phys. Rev. B

Magnetic Order of the Hexagonal Rare Earth Manganite Dy 0.5 Y 0.5 MnO 3

August 26, 2011
Author(s)
Joel Helton, Deepak Singh, Harikrishnan S. Nair, Suja Elizabeth
Hexagonal Dy 0.5Y 0.5MnO 3, a multiferroic rare earth manganite with geometrically frustrated antiferromagnetism, has been investigated with neutron diffraction measurements. Below 2.4 K magnetic order is observed on both the Mn (antiferromagnetic) and Dy

Dzyaloshinskii-Moriya Interaction and Spin Re-Orientation Transition in the Frustrated Kagome Lattice Antiferromagnet

June 9, 2011
Author(s)
K. Matan, B. M. Bartlett, Joel Helton, V. Sikolenko, S. Mat'as, K. Prokes, Ying Chen, Jeffrey W. Lynn, D. Grohol, T. J. Sato, M. Tokunaga, D. G. Nocera, Y. S. Lee
Magnetization, specific heat, and neutron scattering measurements were performed to study a magnetic transition in jarosite, a spin-5/2} kagome lattice antiferromagnet. When a magnetic field is applied perpendicular to the kagome plane, magnetizations in