A5060778115- Topological Materials and Phenomena
- Graphene research and applications
- Rare-earth and actinide compounds
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Inorganic Chemistry and Materials
- Solid-state spectroscopy and crystallography
- Thermodynamic and Structural Properties of Metals and Alloys
- 2D Materials and Applications
- Organic and Molecular Conductors Research
- Quantum many-body systems
- Molecular Junctions and Nanostructures
- Theoretical and Computational Physics
- Gas Sensing Nanomaterials and Sensors
- Ferroelectric and Negative Capacitance Devices
- Nuclear Materials and Properties
- Catalysis and Oxidation Reactions
- Radioactive element chemistry and processing
- Magnetic and transport properties of perovskites and related materials
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- Advanced Memory and Neural Computing
University of California, Santa Barbara
2022-2023
Lawrence Berkeley National Laboratory
2018-2020
University of California, Berkeley
2016-2020
2D layered materials have emerged in recent years as a new platform to host novel electronic, optical, or excitonic physics and develop unprecedented nanoelectronic energy applications. By definition, these are strongly anisotropic between the basal plane cross plane. The structural property anisotropies inside their plane, however, much less investigated. Black phosphorus, for example, is material that has such in-plane anisotropy. Here, rare chemical form of arsenic, called black-arsenic...
Abstract Co $$_{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math> Sn $$_{2}$$ xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math> S is a ferromagnetic Weyl semimetal that has been the subject of intense scientific interest due to its large anomalous Hall effect. We show coupling this material’s topological properties...
Electrons in materials with linear dispersion behave as massless Weyl- or Dirac-quasiparticles, and continue to intrigue due their close resemblance elusive ultra-relativistic particles well potential for future electronics. Yet the experimental signatures of Weyl-fermions are often subtle indirect, particular if they coexist conventional, massive quasiparticles. Here we show a pronounced anomaly magnetic torque Weyl semimetal NbAs upon entering quantum limit state high fields. The changes...
We present the crystal structure, electronic and transport properties of material YbMnSb$_2$, a candidate system for investigation Dirac physics in presence magnetic order. Our measurements reveal that this is low-carrier-density semimetal with 2D Fermi surface arising from dispersion, consistent predictions density functional theory calculations antiferromagnetic system. The low temperature resistivity very large, suggesting scattering highly efficient at dissipating momentum despite its...
A superconductor with broken time reversal and inversion symmetry may exhibit nonreciprocal charge transport, including a critical current, also known as superconducting diode effect. We report an intrinsic effect in polar strontium titanate film. Differential resistance measurements reveal state whose depairing current is polarity dependent. There is, however, no measurable deviation from Ohmic behavior, implying that this does not arise bulk magnetochiral anisotropy. In the entire...
ARPES reveals how correlated electrons reconcile competing interactions by separating them orbital symmetry.
We study the intrinsic electronic anisotropy and fermiology of quasi-one-dimensional superconductor ${\mathrm{Ta}}_{4}{\mathrm{Pd}}_{3}{\mathrm{Te}}_{16}$. Below ${T}^{*}=20$ K, we detect a thermodynamic phase transition that predominantly affects conductivity perpendicular to chains. The relates presence charge order precedes superconductivity. Remarkably, Fermi surface pockets detected by de Haas--van Alphen oscillations are unaffected this transition, suggesting ordered state does not...
Hybrid structures between conventional, s-wave superconductors, and two-dimensional topological insulators (2D TIs) are a promising route to superconductivity. Here, we investigate planar Josephson junctions fabricated from hybrid that use thin films of cadmium arsenide (Cd3As2) as the 2D TI material. Measurements superconducting interference patterns in perpendicular magnetic field used extract information about spatial distribution supercurrent. We show distinctly different with without...
A bulk crystal of cadmium arsenide is a three-dimensional Dirac semimetal, but, in thin film, it can behave like topological insulator. This tunability provides unique opportunities to manipulate and explore insulator phase. However, an obstacle engineering such the subtlety transport-based discriminants for phases. In this work, quantum capacitance arsenide-based heterostructures two direct experimental signatures physics: insulating Landau level at zero energy that does not disperse...
Cadmium arsenide (Cd3As2) thin films feature a two-dimensional topological insulator (2D TI) phase for certain thicknesses, which theoretically hosts set of counterpropagating helical edge states that are characteristic quantum spin Hall (QSH) insulator. In devices containing electrostatically defined junctions and magnetic fields below critical value, chiral modes the effect can coexist with QSH-like modes. this work, we use point contact (QPC) device to characterize in 2D TI Cd3As2...
Spin orbit assisted Mott insulators such as sodium iridate (${\mathrm{Na}}_{2}{\mathrm{IrO}}_{3}$) have been an important subject of study in recent years. In these materials, the interplay electronic correlations, spin-orbit coupling, crystal field effects, and a honeycomb arrangement ions bring exciting ground states, predicted frame Kitaev model. The insulating character ${\mathrm{Na}}_{2}{\mathrm{IrO}}_{3}$ has hampered its integration to device, desirable for applications, manipulation...
Topological materials are promising candidates in fault-tolerant quantum information processing architectures, making it essential to understand the dephasing mechanisms these materials. Here, we investigate gated, nanoscale mesas fabricated on thin films of cadmium arsenide (Cd3As2), a three-dimensional Dirac semimetal that can be tuned into different topological phases. We observe two independent types conductance oscillations, one as function applied magnetic field and other gate voltage....
Our understanding of correlated electron systems is vexed by the complexity their interactions. Heavy fermion compounds are archetypal examples this physics, leading to exotic properties that weave together magnetism, superconductivity and strange metal behavior. The Kondo semimetal CeSb an unusual example where different channels interaction not only coexist, but physical signatures coincident, decades debate about microscopic picture describing interactions between $f$ moments itinerant...
Two-dimensional (2D) layered materials emerge in recent years as a new platform to host novel electronic, optical or excitonic physics and develop unprecedented nanoelectronic energy applications. By definition, these are strongly anisotropic between within the basal plane cross plane. The structural property anisotropies inside their plane, however, much less investigated. Herein, we report rare chemical form of arsenic, called black-arsenic (b-As), an extremely semiconductor. We have...
Hybrid structures between conventional, s-wave superconductors and two-dimensional topological insulators (2D TIs) are a promising route to superconductivity. Here, we investigate planar Josephson junctions fabricated from hybrid that use thin films of cadmium arsenide (Cd3As2) as the 2D TI material. Measurements superconducting interference patterns in perpendicular magnetic field used extract information about spatial distribution supercurrent. We show distinctly different with without...