Researchers used resonant magnetic scattering measurements at beamline 6-ID-B to probe magnetic ordering in Na2IrO3, a material where anisotropic exchange (Kitaev) interactions dominate over isotropic (Heisenberg) exchange interactions. Spin-orbit coupling in heavy Ir atoms is at the root of the bond-directional exchange interactions. In the absence of competing Heisenberg interactions, a quantum spin liquid ground state can emerge when the geometrical arrangement of Ir magnetic moments leads to frustration.
Researchers used x-ray resonant scattering measurements at 6-ID-B to probe the collapse of magnetic ordering in Mott insulator iridate Sr3Ir2O7 as electrons are doped with La doping at the Sr site. The first-order collapse of magnetic order coincided with emergence of a metallic state.
Researchers used XAS (4-ID-D) and resonant XRD (6-ID-B) to study the role of electron-lattice coupling in the metal-insulator transition (MIT) of rare-earth nickelates by controlling lattice distortions via strain manipulation in epitaxial films. Manipulation of electrical conductivity may lead to novel electronic sensors and devices.
Researchers used resonant XRD (6-ID-B) and XAS (4-ID-D) to probe emergence of a “Polar metal” at the strained interface of an oxide heterostructure in an attempt to accelerate discovery of multifunctional materials with ability to perform simultaneous electrical, magnetic and optical functions.
Researchers used XRD (6-ID-B) and XAS/XMCD (4-ID-D) techniques to probe the effects of dimensional confinement in manganite/iridate superlattices with an eye at enabling all-oxide spintronics
Layer by layer, University of Tennessee, Knoxville physicists are exploring the frontiers of tuning material properties down to the atomic level. Experimenting with the stacking pattern of superlattices at the U.S. Department of Energy’s Advanced Photon Source, the UT researchers and their colleagues investigated inter- and intra-layer dynamics to learn more about magnetism on the nanoscale, with potential connections to high-temperature superconductivity and spintronics.
Sometimes a little frustration and disorder can be a good thing, at least in the quest for the elusive and exotic state of matter known as a quantum spin liquid (QSL). In such systems, the electrons are strongly “entangled,” a quantum phenomenon that is the basis of quantum computing but has proven extremely difficult to recreate except under tightly controlled laboratory environments. But QSLs naturally form such states, arising from their strong interactions (or correlations) that also serve to protect their entanglement from environmental influences. One class of these systems is the Kitaev quantum spin liquid, which takes advantage of anisotropic magnetic interactions on a honeycomb lattice.
Two-dimensional (2-D) crystalline films often exhibit interesting physical characteristics, such as unusual magnetic or electric properties. By layering together distinct crystalline thin films, a so-called “superlattice” is formed. Due to their close proximity, the distinct layers of a superlattice may significantly affect the properties of other layers. In this research, single 2-D layers of strontium iridium oxide were sandwiched between either one, two, or three layers of strontium titanium oxide to form three distinct superlattices. Researchers then used x-ray scattering at the U.S. Department of Energy’s Advanced Photon Source to probe the magnetic structure of each superlattice.
Sometimes a good theory just needs the right materials to make it work. That’s the case with recent findings by University of Tennessee, Knoxville’s physicists and their colleagues, who designed a two-dimensional magnetic system that points to the possibility of devices with increased security and efficiency, using only a small amount of energy. The researchers studied the hidden physical properties of the material by utilizing high-brightness x-rays from the U.S. Department of Energy’s Advanced Photon Source, an Office of Science user facility at Argonne National Laboratory.
4-ID-D, 6-ID-B,C, 33-BM-C
A multi-national team of researchers using the U.S. Department of Energy’s APS probed the magnetic and crystalline properties of two superlattices and described magnetic tunability that should prove applicable to numerous other superlattice systems, which may be adapted for improved electronic devices.
6-ID-B,C, 27-ID-B, 33-BM-C