A5005558406- Topological Materials and Phenomena
- Graphene research and applications
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Theoretical and Computational Physics
- Advanced Condensed Matter Physics
- Quantum Dots Synthesis And Properties
University of California, Davis
2021-2022
${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ is a magnetic Weyl semimetal, in which ferromagnetic ordering at 177 K predicted to stabilize points. We perform temperature and spatial dependent angle-resolved photoemission spectroscopy measurements through the Curie (${T}_{c}$), show large band shifts renormalization concomitant with onset of magnetism. argue that evolves from Mott ferromagnet below ${T}_{c}$ correlated metallic state above ${T}_{c}$. To understand magnetism, we derive...
${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ is an ideal three-dimensional topological insulator in which the chemical potential can be brought into bulk band gap with antimony doping. Here, we utilize ultrafast time-resolved transient reflectivity to characterize photoexcited carrier decay ${\mathrm{Bi}}_{2\ensuremath{-}x}{\mathrm{Sb}}_{x}{\mathrm{Se}}_{3}$ nanoplatelets. We report a substantial slowing of relaxation time bulk-insulating as compared $n$-type bulk-metallic at low temperatures,...
Abstract Chemical modifications such as intercalation can be used to modify surface properties or further functionalize the states of topological insulators (TIs). Using ambient pressure x-ray photoelectron spectroscopy, we report copper migration in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> mathvariant="normal">u</mml:mi> </mml:mrow> <mml:mi>x</mml:mi> </mml:msub> mathvariant="normal">B</mml:mi>...
Chemical modifications such as intercalation can be used to modify surface properties or further functionalize the states of topological insulators. Using ambient pressure X-ray photoelectron spectroscopy, we report copper migration in $\text{Cu}_{x}\text{Bi}_2\text{Se}_3$, which occurs on a timescale hours days after initial cleaving. The increase near-surface proceeds along with oxidation sample and large changes selenium content. These complex are modelled core-level spectroscopy...