A5074899473- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Topological Materials and Phenomena
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Magnetic Properties of Alloys
- Superconducting Materials and Applications
- High-pressure geophysics and materials
- Atomic and Subatomic Physics Research
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties and Applications
- Advanced NMR Techniques and Applications
- Electronic and Structural Properties of Oxides
- Phase-change materials and chalcogenides
- Magnetic Field Sensors Techniques
- Thermography and Photoacoustic Techniques
- Advanced Materials Characterization Techniques
- Advanced Sensor Technologies Research
- Advanced Chemical Physics Studies
- Nuclear Physics and Applications
- Commutative Algebra and Its Applications
- Hemodynamic Monitoring and Therapy
- Superconductivity in MgB2 and Alloys
- Quantum Chromodynamics and Particle Interactions
- Advanced Algebra and Logic
University of Michigan
2014-2018
Christian Bilingual University of Congo
2018
Instituto Nacional de Matemática Pura e Aplicada
2012
General Electric (Germany)
1996
Lockheed Martin (United States)
1996
University of California, Berkeley
1975
In Kondo insulator samarium hexaboride SmB$_6$, strong correlation and band hybridization lead to an insulating gap a diverging resistance at low temperature. The divergence ends about 5 Kelvin, behavior recently demonstrated arise from the surface conductance. However, questions remain whether where topological state exists. Quantum oscillations have not been observed map Fermi surface. We solve problem by resolving Landau Level quantization topology using torque magnetometry. suggests two...
Quantum computers need new materials to protect their delicate quantum states. Evidence for such a material---a topological superconductor---has been detected as breaking of rotational symmetry in crystal Nb-doped Bi${}_{2}$Se${}_{3}$.
In metals, orbital motions of conduction electrons on the Fermi surface are quantized in magnetic fields, which is manifested by quantum oscillations electrical resistivity. This Landau quantization generally absent insulators. Here we report a notable exception an insulator, ytterbium dodecaboride (YbB12). Despite much larger than that resistivity YbB12 exhibits profound oscillations. unconventional oscillation shown to arise from insulating bulk, yet temperature dependence their amplitude...
Topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ has shown a number of interesting physical properties. Doping with copper or strontium been demonstrated to make the material superconducting and potentially even topological superconductor. The recent discovery niobium-doped reveals an exciting new phenomenon, coexistence superconductivity magnetic ordering, as well signatures odd-parity $p$-wave order. To understand this detailed knowledge electronic structure is needed. We present...
Significance We obtain the magnetic phase diagram in underdoped cuprate YBa 2 Cu 3 O y using torque magnetometry at temperatures 0.3–70 K and fields up to 45 T. At low fields, vortices (quantized flux tubes) form a vortex solid that is strongly pinned lattice. large melting of liquid produces nonzero dissipation. However, persists above 41 have also mapped out “transition” which charge-density–wave state (observed X-ray diffraction experiments) becomes stable. Our results show that, intense...
The recent conjecture of a topologically protected surface state in ${\mathrm{SmB}}_{6}$ and the verification robust conduction below 4 K have prompted large effort to understand states. Conventional Hall transport measurements allow current flow on all surfaces topological insulator, so such are influenced by contributions from multiple varying character. Instead, we study magnetotransport using Corbino geometry, which can directly measure conductivity single, independent surface. Both...
${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ has drawn much attention as the leading candidate to be first topological superconductor and realization of coveted Majorana particles in a condensed matter system. However, there been increasing controversy about nature its superconducting phase. This study sheds light on ambiguity normal-state electronic state by providing complete look at quantum oscillations magnetization high magnetic fields up 31 T. Our focuses angular dependence...
Kondo insulator samarium hexaboride (SmB6) has been intensely studied in recent years as a potential candidate of strongly correlated topological insulator. One the most exciting phenomena observed SmB6 is clear quantum oscillations appearing magnetic torque at low temperature despite insulating behavior resistance. These show multiple frequencies and varied effective masses. The origin oscillation is, however, still under debate with evidence both two-dimensional Fermi surfaces...
Herbertsmithite ${\mathrm{ZnCu}}_{3}(\mathrm{OH}){}_{6}{\mathrm{Cl}}_{2}$ is a kagome lattice antiferromagnet with spin-1/2 and has been demonstrated to be likely candidate of spin liquid by number recent experiments. The high-field magnetization the complicated due presence few percent extra Cu impurities sitting on interlayer metallic sites. To determine magnetic ground state lattice, we measured single crystalline using torque magnetometry down base temperatures 20 mK in intense field as...
The mixed valent compound SmB6 is of high current interest as the first candidate example topologically protected surface states in a strongly correlated insulator and also possible host for an exotic bulk many-body state that would manifest properties both metal. Two different de Haas van Alphen (dHvA) experiments have each supported one these possibilities, while angle resolved photoemission spectroscopy (ARPES) (001) has first, but without quantitative agreement to dHvA results. We...
The thermal Hall effect is the analog of electrical effect. Rarely observed in normal metals, signals have been argued to be a key property for number strongly correlated materials, such as high temperature superconductors, topological insulators, and quantum magnets. observation requires precise measurement intense magnetic fields. Particularly at low temperature, resistive thermometers strong dependence on field, which makes them unsuitable this purpose. We created capacitive instead...
The current interest in materials supporting topological states calls for detailed electronic-structure characterization, via magnetometry intense magnetic fields. A quartz tuning fork (QTF) could be an advantageous platform this very challenging task, but the technique has not been widely studied. authors demonstrate that a particular QTF configuration allows $t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}q\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}e$...
Self-reflection on learning experiences constitutes a fundamental cognitive process, essential for the consolidation of knowledge and enhancement efficacy. However, traditional methods to facilitate reflection often face challenges in personalization, immediacy feedback, engagement, scalability. Integration Large Language Models (LLMs) into process could mitigate these limitations. In this paper, we conducted two randomized field experiments undergraduate computer science courses investigate...