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Full-Text Articles in Physics

Unconventional Anomalous Hall Effect From Antiferromagnetic Domain Walls Of Nd2Ir2O7 Thin Films, Woo Jin Kim, John H. Gruenewald, Taekoo Oh, Sangmo Cheon, Bongju Kim, Oleksandr B. Korneta, Hwanbeom Cho, Daesu Lee, Yoonkoo Kim, Miyoung Kim, Je-Geun Park, Bohm-Jung Yang, Ambrose Seo Sep 2018

Unconventional Anomalous Hall Effect From Antiferromagnetic Domain Walls Of Nd2Ir2O7 Thin Films, Woo Jin Kim, John H. Gruenewald, Taekoo Oh, Sangmo Cheon, Bongju Kim, Oleksandr B. Korneta, Hwanbeom Cho, Daesu Lee, Yoonkoo Kim, Miyoung Kim, Je-Geun Park, Bohm-Jung Yang, Ambrose Seo

Physics and Astronomy Faculty Publications

Ferroic domain walls (DWs) create different symmetries and ordered states compared with those in single-domain bulk materials. In particular, the DWs of an antiferromagnet with noncoplanar spin structure have a distinct symmetry that cannot be realized in those of their ferromagnet counterparts. In this paper, we show that an unconventional anomalous Hall effect (AHE) can arise from the DWs of a noncoplanar antiferromagnet, Nd2Ir2O7. Bulk Nd2Ir2O7 has a cubic symmetry; thus, its Hall signal should be zero without an applied magnetic field. The DWs generated in this material break …


Observation Of A Pressure-Induced Transition From Interlayer Ferromagnetism To Intralayer Antiferromagnetism In Sr4Ru3O10, H. Zheng, W. H. Song, J. Terzic, H. D. Zhao, Y. F. Ni, Lance E. Delong, P. Schlottmann, G. Cao Aug 2018

Observation Of A Pressure-Induced Transition From Interlayer Ferromagnetism To Intralayer Antiferromagnetism In Sr4Ru3O10, H. Zheng, W. H. Song, J. Terzic, H. D. Zhao, Y. F. Ni, Lance E. Delong, P. Schlottmann, G. Cao

Physics and Astronomy Faculty Publications

Sr4Ru3O10 is a Ruddlesden-Popper compound with triple Ru-O perovskite layers separated by Sr-O rock-salt layers. This compound presents a rare coexistence of interlayer (c-axis) ferromagnetism and intralayer (basal-plane) metamagnetism at ambient pressure. Here we report the observation of pressure-induced, intralayer itinerant antiferromagnetism arising from the interlayer ferromagnetism. The application of modest hydrostatic pressure generates an anisotropy that may cause a flattening and a tilting of RuO6 octahedra. All magnetic and transport results from this study indicate these lattice distortions diminish the c-axis ferromagnetism and basal-plane metamagnetism, and induce a basal-plane antiferromagnetic state. …


Quadrupolar Quantum Criticality On A Fractal, Jonathan D'Emidio, Simon Lovell, Ribhu K. Kaul May 2018

Quadrupolar Quantum Criticality On A Fractal, Jonathan D'Emidio, Simon Lovell, Ribhu K. Kaul

Physics and Astronomy Faculty Publications

We study the ground state ordering of quadrupolar ordered S = 1 magnets as a function of spin dilution probability p on the triangular lattice. In sharp contrast to the ordering of S = 1/2 dipolar Néel magnets on percolating clusters, we find that the quadrupolar magnets are quantum disordered at the percolation threshold, p = p. Further we find that long-range quadrupolar order is present for all p < p and vanishes first exactly at p. Strong evidence for scaling behavior close to p points to an unusual quantum criticality without fine tuning that …


Electrical Control Of Structural And Physical Properties Via Strong Spin-Orbit Interactions In Sr2Iro4, Gang Cao, Jasminka Terzic, H. D. Zhao, H. Zheng, Lance E. De Long, Peter S. Riseborough Jan 2018

Electrical Control Of Structural And Physical Properties Via Strong Spin-Orbit Interactions In Sr2Iro4, Gang Cao, Jasminka Terzic, H. D. Zhao, H. Zheng, Lance E. De Long, Peter S. Riseborough

Physics and Astronomy Faculty Publications

Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic Mott state is sufficient to attain that goal. The antiferromagnetic insulator Sr2IrO4 provides a model system in which strong SOI lock canted Ir magnetic moments to IrO6 octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the Néel temperature and drives a large, nonlinear lattice expansion that closely tracks the magnetization, increases the …


Doping Evolution Of Magnetic Order And Magnetic Excitations In (Sr1-XLaX)3Ir2O7, Xingye Lu, D. E. Mcnally, M. Moretti Sala, Jsaminka Terzic, M. H. Upton, D. Casa, G. Ingold, Gang Cao, T. Schmitt Jan 2017

Doping Evolution Of Magnetic Order And Magnetic Excitations In (Sr1-XLaX)3Ir2O7, Xingye Lu, D. E. Mcnally, M. Moretti Sala, Jsaminka Terzic, M. H. Upton, D. Casa, G. Ingold, Gang Cao, T. Schmitt

Physics and Astronomy Faculty Publications

We use resonant elastic and inelastic x-ray scattering at the Ir-L3 edge to study the doping-dependent magnetic order, magnetic excitations, and spin-orbit excitons in the electron-doped bilayer iridate (Sr1−xLax)3Ir2O7 (0 ≤ x ≤ 0.065). With increasing doping x, the three-dimensional long range antiferromagnetic order is gradually suppressed and evolves into a three-dimensional short range order across the insulator-to-metal transition from x = 0 to 0.05, followed by a transition to two-dimensional short range order between x = 0.05 and 0.065. Because of the interactions between the J …


Simultaneous Metal-Insulator And Antiferromagnetic Transitions In Orthorhombic Perovskite Iridate Sr0.94Ir0.78O2.68 Single Crystals, Hao Zheng, Jsaminka Terzic, Feng Ye, X. G. Wan, D. Wang, Jinchen Wang, Xiaoping Wang, P. Schlottmann, Shujuan Yuan, Gang Cao Jun 2016

Simultaneous Metal-Insulator And Antiferromagnetic Transitions In Orthorhombic Perovskite Iridate Sr0.94Ir0.78O2.68 Single Crystals, Hao Zheng, Jsaminka Terzic, Feng Ye, X. G. Wan, D. Wang, Jinchen Wang, Xiaoping Wang, P. Schlottmann, Shujuan Yuan, Gang Cao

Center for Advanced Materials Faculty Publications

The orthorhombic perovskite SrIrO3 is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose an insulating state. We report results of our investigation of bulk single-crystal Sr0.94Ir0.78O2.68 or Ir-deficient, orthorhombic perovskite SrIrO3. It retains the same crystal structure as stoichiometric SrIrO3 but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition occurring in the basal-plane resistivity at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear temperature dependence up to 800 K but the strong …


Temperature Dependence Of Anisotropic Magnetoresistance In Antiferromagnetic Sr2Iro4, C. Wang, H. Seinige, Gang Cao, J.-S. Zhou, J. B. Goodenough, M. Tsoi Feb 2015

Temperature Dependence Of Anisotropic Magnetoresistance In Antiferromagnetic Sr2Iro4, C. Wang, H. Seinige, Gang Cao, J.-S. Zhou, J. B. Goodenough, M. Tsoi

Center for Advanced Materials Faculty Publications

Temperature-dependent magnetotransport properties of the antiferromagnetic semiconductor Sr2IrO4 are investigated with point-contact devices. The point-contact technique allows to probe very small volumes and, therefore, to look for electronic transport on a microscopic scale. Point-contact measurements with single crystals of Sr2IrO4 were intended to see whether the additional local resistance associated with a small contact area between a sharpened Cu tip and the antiferromagnet shows magnetoresistance (MR) such as that seen in bulk crystals. Point-contact measurements at liquid nitrogen temperature revealed large MRs (up to 28%) for modest magnetic fields (250 mT) applied within an …