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Search Publications by: Jose A Rodriguez (Assoc)

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Displaying 1 - 25 of 56

Phonon lifetimes and mode softening in cubic Cs2AgBiBr6

June 2, 2025
Author(s)
Zihan Zhang, Peter Gehring, Adam H. Slavney, Julian A. Vigil, Tao Hong, Jose Rodriguez Rivera, Johan Klarbring, Hemamala Karunadasa, Michael Toney, Nicholas Weadock
Metal halide perovskites (MHPs) have emerged as noteworthy candidates for photovoltaic applications in recent years. Their high power-conversion efficiency is largely attributed to the structure-function relationship, which is not well understood. In this

Continuum of magnetic excitations in the Kitaev honeycomb iridate D3LiIr2O6

March 29, 2025
Author(s)
Thomas Halloran, Yishu Wang, Kemp Plumb, M. B. Stone, Barry Winn, M. K. Graves-Brook, Jose Rodriguez Rivera, Yiming Qiu, Prashant Chauhan, Johannes Knolle, Roderich Moessner, N. Armitage, Tomohiro Takayama, Hidenori Takagi, Collin L. Broholm
Inelastic neutron scattering (INS) measurements of powder D3(7Li)(193Ir)2O6 reveal low energy magnetic excitations with a scattering cross-section that is broad in ∣Q∣ and energy transfer. The magnetic nature of the excitation spectrum is demonstrated by

Connection between f-electron correlations and magnetic excitations in UTe2

January 4, 2025
Author(s)
Thomas Halloran, Peter Czajka, Gicela Saucedo Salas, Corey Frank, Jose Rodriguez Rivera, Daniel Mazzonne, Jakob Lass, Nicholas Butch
Abstract The detailed anisotropic dispersion of the low-temperature, low-energy magnetic excitations of the candidate spin-triplet superconductor UTe 2 is revealed using inelastic neutron scattering. The magnetic excitations emerge from the Brillouin zone

Time evolution of a pumped molecular magnet - a time resolved inelastic neutron scattering study

January 1, 2025
Author(s)
T. Reeder, Paraj Titum, J. Kindervater, Qiang Ye, Jose Rodriguez Rivera, Yiming Qiu, Nicholas C. Maliszewskyj, T. McQueen, Collin L. Broholm
ntroducing an experimental technique of time-resolved inelastic neutron scattering (TRINS), we explore the time-dependent effects of resonant pulsed microwaves on the molecular magnet Cr8F8Piv16. The octagonal rings of magnetic Cr3+ atoms with

Spin-orbital order and excitons in magnetoresistive HoBi

March 22, 2023
Author(s)
Jonathan N. Gaudet, H. Yang, E. Smith, T. Halloran, J. Clancy, Jose Rodriguez Rivera, Guangyong Xu, Yang Zhao, Wangchun Chen, G. Sala, Adam A. Aczel, B. Gaulin, Fazel Tafti, Collin L. Broholm
The magnetism of the rock-salt fcc rare-earth monopnictide HoBi, a candidate topological material with extreme magnetoresistance, is investigated. From the Ho3+ non-Kramers J=8 spin-orbital multiplet, the cubic crystal electric field yields six near

Unravelled and Glassy Magnetism in PbFe 1/2 Nb 1/2 O 3 - (2) Neutron Scattering

October 11, 2022
Author(s)
C. Stock, B. Roessli, Peter M. Gehring, Jose Rodriguez Rivera, N. Giles-Donovan, S. Cochran, Guangyong Xu, P. Manuel, M. J. Gutmann, William D. Ratcliff, T. Fennell, Y. Su, X. Li, H. Luo
We apply neutron scattering to investigate the magnetism in the relaxor ferroelectric PbFe 1/2Nb 1/2O 3 (PFN). Similar to the lack of spatially long-range ferroelectric order in prototypical relaxors like Pb(Mg,Zn) 1/3Nb 2/3O 3 (PMN and PZN), spatially

Symmetry of Magnetic Correlations in Spin-Triplet Superconductor UTe2

April 5, 2022
Author(s)
Nicholas Butch, Sheng Ran, Shanta Saha, Paul Neves, Mark P. Zic, Johnpierre N. Paglione, Yegor N. Vekhov, Sergiy Gladchenko, Jose Rodriguez Rivera
The temperature dependence of the low-energy magnetic excitations in the spin-triplet superconductor UTe2 was measured via inelastic neutron scattering in the normal and superconducting states. These excitations have a peak instensity at 4 meV, follow the

Spin Dynamics in the Skyrmion-Host Lacunar Spinel GaV 4 S 8

December 20, 2021
Author(s)
G. Pokharel, H. Arachchige, S. Gao, S.-H. Do, R. Fishman, G. Ehlers, Yiming Qiu, Jose Rodriguez Rivera, M. B. Stone, H. Zhang, Stephen Wilson, D. Mandrus, A. Christianson
In the lacunar spinel GaV 4S 8, the interplay of spin, charge, and orbital degrees of freedom produces a rich phase diagram that includes an unusual Neel-type skyrmion phase composed of molecular spins. To provide ´ insight into the interactions underlying

Metastable Antiphase Boundary Ordering in CaFe 2 O 4

September 2, 2021
Author(s)
H. Lane, E. Rodriguez, H. C. Walker, Ch. Niedermayer, U. Stuhr, R. I. Bewley, D. J. Voneshen, M. A. Green, Jose Rodriguez Rivera, P. Fouquet, S.-W. Cheong, J. P. Attfield, R. A. Ewings, C. Stock

Weyl-mediated helical magnetism in NdAlSi

August 19, 2021
Author(s)
Jonathan Gaudet, Hung-Yu Yang, Santu Baidya, Baozhu Lu, Guangyong Xu, Yang Zhao, Jose Rodriguez Rivera, Christina M. Hoffman, David E. Graf, Darius H. Torchinsky, Predrag Nikolic, David Vanderbilt, Fazel Tafti, Collin L. Broholm
Emergent relativistic quasiparticles in Weyl semimetals are the source of exotic electronic properties such as surface Fermi arcs, the anomalous Hall effect and negative magnetoresistance, all observed in real materials. Whereas these phenomena highlight

Monopolar and dipolar relaxation in spin ice Ho2Ti2O7

June 16, 2021
Author(s)
Yishu Wang, T. Reeder, Y. Karaki, J. Kindervater, T. Halloran, Nicholas C. Maliszewskyj, Yiming Qiu, Jose Rodriguez Rivera, Sergiy Gladchenko, S. M. Koohpayeh, S. Nakatsuji, Collin L. Broholm
Ferromagnetically interacting Ising spins on the pyrochlore lattice of corner-sharing tetrahedra form a highly degenerate manifold of low-energy states. A spin flip relative to this "spin-ice" manifold can fractionalize into two oppositely charged magnetic

Pristine Quantum Criticality in a Kondo Semimetal

May 19, 2021
Author(s)
Wesley T. Fuhrman, Andrey Sidorenko, Jonathan Hanel, Hannes Winkler, Andrey Prokofiev, Jose Rodriguez Rivera, Yiming Qiu, Peter Blaha, Qimiao Si, Collin L. Broholm, Silke Paschen
The observation of quantum criticality in diverse classes of strongly correlated electron systems has been instrumental in establishing ordering principles, discovering new phases, and identifying the relevant degrees of freedom and interactions. At focus

Kitaev Interactions in the Co Honeycomb Antiferromagnets Na 3 Co 2 SbO 6 and Na 2 Co 2 TeO 6

December 24, 2020
Author(s)
M. Songvilay, J. Robert, Jose Rodriguez Rivera, William D. Ratcliff, F. Damay, V. Baledent, M. Jimenez-Ruiz, P. Lejay, E. Pachoud, A. Hadj-Azzem, V. Simonet, C. Stock
Co 2+ ions in an octahedral crystal field, stabilize a jeff = 1⁄2 ground state with an orbital degree of freedom and and have been recently put forward for realising Kitaev interactions, a prediction that we have tested by investigating spin dynamics in

Intertwined Density Waves in a Metallic Nickelate

November 26, 2020
Author(s)
Junjie Zhang, D. Phelan, A. S. Botana, Yu-Sheng Chen, Hong Zheng, M. Krogstad, Suyin G. Wang, Yiming Qiu, Jose Rodriguez Rivera, R. Osborn, S. Rosenkranz, M. R. Norman, J. F. Mitchell
Nickelates are a rich class of materials, ranging from insulating magnets to superconductors. But for stoichiometric materials, insulating behavior is the norm, as for most late transition metal oxides. Notable exceptions are the 3D perovskite LaNiO 3, an

Magnetic Order and Instability in Newly Synthesized CoSeAs Marcasite

May 13, 2020
Author(s)
Yiyao Chen, G. Yumnam, A. Dahal, Jose Rodriguez Rivera, Guangyong Xu, T. Heitmann, D. K. Singh
Marcasite class of compounds provide facile platform to explore novel phenomena of fundamental and technological importance, such as unconventional superconductivity or high performance electrocatalyst. We report the synthesis and experimental

Low-Energy Magnons in the Chiral Ferrimagnet Cu 2 OSeO 3 : A Coarse-Grained Approach

April 8, 2020
Author(s)
Yi Luo, G. G. Marcus, Benjamin Trump, J. Kindervater, M. B. Stone, Jose Rodriguez Rivera, Yiming Qiu, T. M. McQueen, O. Tchernyshyov, Collin L. Broholm
We report a comprehensive neutron scattering study of low energy magnetic excitations in the breathing pyrochlore helimagnetic Cu 2OSeO 3. Fully documenting the four lowest energy magnetic modes that leave the ferrimagnetic configuration of the "strong

Ungapped Magnetic Excitations Beyond Hidden Order in URu 2-x Re x Si 2

February 12, 2020
Author(s)
Nicholas P. Butch, Jose A. Rodriguez, M. Brian Maple
We use inelastic neutron scattering measurements to show that the energy gap in the magnetic excitations of URu 2Si 2, induced by the Hidden Order transition, is closed by Re substitution. The magnetic excitations remain ungapped in compositions where the

Wide-Angle Polarization Analysis on the Multi-Axis Crystal Spectrometer for the Study of Collective and Single Particle Dynamics of Methanol at its Prepeak

July 1, 2019
Author(s)
Wangchun Chen, Shannon M. Watson, Yiming Qiu, Jose Rodriguez Rivera, Antonio Faraone
Neutron polarization analysis capability with a large scattering angle and momentum transfer coverage has not been widely implemented for the separation of coherent and incoherent quasi-elastic neutron scattering (QENS) spectra. A feasibility test for soft

Spin Stripe Order in a Square Planar Trilayer Nickelate

June 18, 2019
Author(s)
Junjie Zhang, D. M. Pajerowski, A. S. Botana, Hong Zheng, Leland Harriger, Jose Rodriguez Rivera, J. Ruff, N. J. Schreiber, B. Wang, Yu-Sheng Chen, Wangchun Chen, M. R. Norman, S. Rosenkranz, J. F. Mitchell, D. Phelan
Trilayer nickelates, which exhibit a high degree of orbital polarization combined with an electron (d 8.67) corresponding to overdoped cuprates, have been recognized as promising candidates for achieving high-T c superconductivity. One such material, La

Continuum of Quantum Fluctuations in a Three-Dimensional S = 1 Heisenberg Magnet

January 1, 2019
Author(s)
K. W. Plumb, Hitesh J. Changlani, A. Scheie, Shu Zhang, J. W. Krizan, Jose Rodriguez Rivera, Yiming Qiu, B. Winn, R. J. Cava, Collin L. Broholm
Spin liquids are a fundamentally new phase of matter that cannot be described by a broken symmetry and have no order parameter. While the quantum entanglement that characterizes a quantum spin liquid is not directly accessible to any current measurement

Local Quantum Phase Transition in YFe 2 Al^d10

July 3, 2018
Author(s)
W. J. Gannon, L. S. Wu, I. A. Zaliznyak, W. H. Xu, A. M. Tsvelik, Yiming Qiu, Jose Rodriguez Rivera, M. C. Aronson
A phase transition occurs when correlated regions of a new phase grow to span the system and the fluctuations within the correlated regions become long-lived. Here we present neutron scattering measurements showing that this conventional picture must be

Screened Moments and Extrinsic In-Gap States in Samarium Hexaboride

April 18, 2018
Author(s)
W. T. Fuhrman, J. R. Chamorro, P. A. Alekseev, J.-M. Mignot, T. Keller, Jose Rodriguez Rivera, Yiming Qiu, P. Nikolic, T. M. McQueen, Collin L. Broholm
The Kondo impurity effect in metals is the result of quantum-mechanical scattering of conduction electrons by magnetic impurities. 1 This process leads to exotic effects such as unconventional superconductivity and an effective electron mass enhanced by 2
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