A5008082211- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Iron-based superconductors research
- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Advanced Chemical Physics Studies
- Intellectual Capital and Performance Analysis
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Inorganic Chemistry and Materials
- Corporate Taxation and Avoidance
- Inorganic Fluorides and Related Compounds
- Magnetic Field Sensors Techniques
- Force Microscopy Techniques and Applications
- Strong Light-Matter Interactions
- Spectroscopy and Quantum Chemical Studies
- ZnO doping and properties
- Particle Accelerators and Free-Electron Lasers
- Rare-earth and actinide compounds
- Quantum, superfluid, helium dynamics
- Magnetic Properties and Applications
University of Colorado Boulder
2020-2023
University of Alabama at Birmingham
2018-2023
The interplay between topology and magnetism is essential for realizing novel topological states including the axion insulator, magnetic Weyl semimetal, etc. An intrinsically ferromagnetic material with only bands at charge neutrality energy has so far remained elusive. By rationally designing natural heterostructure consisting of [MnBi2Te4] septuple layers [Bi2Te3] quintuple layers, we report MnBi8Te13 as first intrinsic clean low-energy band structure. Based on thermodynamic, transport...
The discovery of superconductivity in planar nickelates raises the question how electronic structure and correlations Ni1+ compounds compare to those Cu2+ cuprate superconductors. Here, we present an angle-resolved photoemission spectroscopy (ARPES) study trilayer nickelate Pr4Ni3O8, revealing a Fermi surface resembling that hole-doped cuprates but with critical differences. Specifically, main portions are extremely similar bilayer cuprates, additional piece can accommodate hole doping. We...
Abstract Tetragonal CuMnAs is a room temperature antiferromagnet with an electrically reorientable Néel vector and Dirac semimetal candidate. Direct measurements of the electronic structure single-crystalline thin films tetragonal using angle-resolved photoemission spectroscopy (ARPES) are reported, including Fermi surfaces (FS) energy-wavevector dispersions. After correcting for chemical potential shift ≈− 390 meV (hole doping), there excellent agreement FS, orbital character bands,...
BaNi2As2 is a structural analog of the pnictide superconductor BaFe2As2, which, like iron-based superconductors, hosts variety ordered phases including charge density waves (CDWs), electronic nematicity, and superconductivity. Upon isovalent Sr substitution on Ba site, nematic orders are suppressed, followed by sixfold enhancement superconducting transition temperature (Tc). To understand mechanisms responsible for Tc, we present high-resolution angle-resolved photoemission spectroscopy...
The search for materials to support the Quantum Anomalous Hall Effect (QAHE) have recently centered on intrinsic magnetic topological insulators (MTIs) including MnBi$_2$Te$_4$ or heterostructures made up of and Bi$_2$Te$_3$. While is itself a MTI, most recent ARPES experiments indicate that surface states this material lack mass gap expected from magnetism-induced time-reversal symmetry breaking (TRSB), with absence likely due disorder. Here, utilizing small-spot scanned across surfaces...
We describe the development of a broadband (0.3-10 THz) optical pump-terahertz probe spectrometer with an unprecedented combination temporal resolution (≤200 fs) operating in external magnetic fields as high 25 T using new Split Florida-Helix magnet system. Using this instrument, we measure transient dynamics gallium arsenide four-quantum well sample after photoexcitation at 800 nm.
We use terahertz time-domain spectroscopy to study gallium arsenide two-dimensional electron gas samples in external magnetic field. measure cyclotron decay as a function of temperature from 0.4 to10Kand quantum confinement dependence the time belowT0=1.2K. In wider well, we observe dramatic enhancement due reduction dephasing and concomitant superradiant these systems. show that 2DEG's depends on both scatteringrateand also distribution scattering angles.
We custom-designed an optical pump-terahertz probe spectrometer to operate under the high external magnetic fields of 25 T Split Florida-Helix and demonstrated instrument use by studying a gallium arsenide multiple quantum well sample. © 2019 The Author(s)
We custom-designed an optical pump-terahertz probe spectrometer to operate under the high external magnetic fields of 25 T Split Florida-Helix and demonstrated instrument use by studying a gallium arsenide multiple quantum well sample.
Tetragonal CuMnAs is a room temperature antiferromagnet with an electrically reorientable N\'eel vector and Dirac semimetal candidate. Direct measurements of the electronic structure single-crystalline thin films tetragonal using angle-resolved photoemission spectroscopy (ARPES) are reported, including Fermi surfaces (FS) energy-wavevector dispersions. After correcting for chemical potential shift $\approx-390$ meV (hole doping), there excellent agreement FS, orbital character bands,...
The recent discovery of superconductivity in hole-doped planar nickelates R1-xSrNiO2 (R=Pr,Nd) raises the foundational question how electronic structure and correlations these Ni1+ compounds compare to those Cu2+ cuprate superconductors. Here, we present an Angle-Resolved Photoemission Spectroscopy (ARPES) study trilayer nickelate Pr4Ni3O8, revealing Fermi surface very similar that cuprates but with a few critical differences. Specifically, main portions are extremely bilayer cuprates,...