A5060498963- Advanced Condensed Matter Physics
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Iron-based superconductors research
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties of Alloys
- Superconducting Materials and Applications
- High-pressure geophysics and materials
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Phase-change materials and chalcogenides
- Thermography and Photoacoustic Techniques
- 2D Materials and Applications
- Perovskite Materials and Applications
- Inorganic Fluorides and Related Compounds
- Multiferroics and related materials
- Spectral Theory in Mathematical Physics
- Nuclear materials and radiation effects
- Quantum many-body systems
- Advanced Thermoelectric Materials and Devices
Los Alamos National Laboratory
2020-2024
Kyoto University
2022-2024
University of Michigan–Ann Arbor
2014-2022
Max Planck Institute for Solid State Research
2019
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...
The recently discovered superconductor UTe 2 is a promising candidate for spin-triplet superconductors, but the symmetry of superconducting order parameter remains highly controversial. Here, we determine gap structure by thermal conductivity ultraclean single crystals. We find that -axis divided temperature κ/ T in zero-temperature limit vanishingly small both magnetic field H ‖ and c axes up to / ∼ 0.2, demonstrating absence nodes around axis contrary previous belief. present results,...
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${}_{3}$.
The two-dimensional spin-$1/2$ kagome Heisenberg antiferromagnet is believed to host quantum spin liquid (QSL) states with no magnetic order, but its ground state remains largely elusive. An important outstanding question concerns the presence or absence of $1/9$ magnetization plateau, where exotic states, including topological ones, are expected emerge. Here we report a recently discovered QSL candidate ${\mathrm{YCu}}_{3}{(\mathrm{OH})}_{6.5}{\mathrm{Br}}_{2.5}$ up 57 T. Above 50 T, clear...
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...
We present magnetotransport data on the ferrimagnet GdMn$_6$Sn$_6$. From temperature dependent we are able to extract a large instrinsic contribution anomalous Hall effect $\sigma_{xz}^{int} \sim$ 32 $\Omega^{-1}cm^{-1}$ and $\sigma_{xy}^{int} 223 $\Omega^{-1}cm^{-1}$, which is comparable values found in other systems also containing kagome nets of transition metals. our transport anisotropy, as well density functional theory calculations, argue that system electronically best described...
Despite extensive investigations, a topological state that hosts Majorana edge modes in the magnetic field-induced quantum disordered of Kitaev candidate material $\alpha$-RuCl$_3$ has been hotly debated. To gain more insight into this issue, we measured thermal Hall conductivity $\kappa_{xy}$ various samples grown by Bridgman method. The results show half-integer effect is intimately related to magnitude longitudinal and N\'{e}el temperature at zero field, both which are sample dependent....
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...
A recent focus of quantum spin liquid (QSL) studies is how disorder/randomness in a QSL candidate affects its true magnetic ground state. The ultimate question whether the survives disorder or leads to "spin-liquid-like" state, such as proposed random-singlet (RS) Since standard feature most candidates, this represents major challenge for candidates. YbMgGaO$_4$, triangular lattice antiferromagnet with effective spin-1/2 Yb$^{3+}$ ions, an ideal system address question, since it shows no...
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...
Abstract Fermionic superfluidity with a nontrivial Cooper-pairing, beyond the conventional Bardeen-Cooper-Schrieffer state, is captivating field of study in quantum many-body systems. In particular, search for superconducting states finite-momentum pairs has long been challenge, but establishing its existence suffered from lack an appropriate probe to reveal momentum. Recently, it proposed that nonreciprocal electron transport most powerful pairs, because directly couples supercurrents. Here...
In conventional superconductors an external magnetic field generally suppresses superconductivity. This results from a simple thermodynamic competition of the superconducting and free energies. this study, we report unconventional features in epitaxial thin film tungsten telluride (WTe
The Kitaev quantum spin liquid (QSL) on the two-dimensional honeycomb lattice epitomizes an entangled topological state, where spins fractionalize into Majorana fermions. This state has aroused tremendous interest because it harbors non-Abelian anyon excitations. half-integer quantized thermal Hall (HIQTH) conductance observed in $\alpha$-RuCl$_3$ is a key signature of these However, fate this topologically nontrivial at intense fields remains largely elusive. Here, we report conductivity...
CeRh$_6$Ge$_4$ is unusual in that its ferromagnetic transition can be suppressed continuously to zero temperature, i.e., a quantum-critical point (QCP), through the application of modest hydrostatic pressure. This discovery has raised possibility QCP may Kondo-breakdown type characterized by jump Fermi volume, which thermopower S measurements should sensitive. Though $S/T$ changes both sign and magnitude around critical pressure P$_{c}\approx{}0.8$ GPa, these are not abrupt but extend over...
A single layer of the transition-metal oxide SrRuO${}_{3}$ remains magnetic and conductive when embedded in a lattice SrTiO${}_{3}$, showing that could be promising material for spintronics applications.
Despite tremendous investigations, a quantum spin liquid (QSL) state realized in spin-1/2 kagome Heisenberg antiferromagnet remains largely elusive. In herbertsmithite $\mathrm{Zn}{\mathrm{Cu}}_{3}{(\mathrm{O}\mathrm{H})}_{6}{\mathrm{Cl}}_{2}$, candidate on the perfect lattice, precisely characterizing intrinsic physics of layers is extremely challenging due to presence interlayer Cu/Zn antisite disorder within its crystal structure. Here we measured specific heat and thermal conductivity...
${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ 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...
UTe
The electronic behavior of the Kondo insulator YbB${}_{12}$ under strong magnetic fields reveals a possible origin quantum oscillations in magnetization and resistivity that suggest development exotic states.