A5071648740- Rare-earth and actinide compounds
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Magnetic Properties of Alloys
- Graphene research and applications
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- 2D Materials and Applications
- Inorganic Chemistry and Materials
- Boron and Carbon Nanomaterials Research
- Theoretical and Computational Physics
- Surface and Thin Film Phenomena
- Multiferroics and related materials
- Organic and Molecular Conductors Research
- Quantum and electron transport phenomena
- Semiconductor materials and interfaces
- High-pressure geophysics and materials
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
Los Alamos National Laboratory
2022-2025
Max Planck Institute for Chemical Physics of Solids
2016-2023
Indian Institute of Science Education and Research Thiruvananthapuram
2015
Abstract Weyl semimetals (WSMs) are topological quantum states wherein the electronic bands disperse linearly around pairs of nodes with fixed chirality, points. In WSMs, nonorthogonal electric and magnetic fields induce an exotic phenomenon known as chiral anomaly, resulting in unconventional negative longitudinal magnetoresistance, chiral-magnetic effect. However, it remains open question to which extent this effect survives when chirality is not well-defined. Here, we establish detailed...
Recently, the existence of massless chiral (Weyl) fermions has been postulated in a class semi-metals with non-trivial energy dispersion.These materials are now commonly dubbed Weyl (WSM).One predicted property is or Adler-Bell-Jackiw anomaly, chirality imbalance presence parallel magnetic and electric fields. In WSM, it expected to induce negative longitudinal magnetoresistance (NMR), effect.Here, we present experimental evidence that observation effect can be hindered by an called "current...
Quantum spin liquids were proposed over 50 years ago, but identifying experimental signatures is extremely difficult. Here, the authors study Yb triangular materials KYbSe${}_{2}$ and NaYbSe${}_{2}$, show that well described by Heisenberg ${J}_{2}$-${J}_{1}$ model. Comparing this material to NaYbSe${}_{2}$ CsYbSe${}_{2}$, a trend emerges where magnetic exchange interactions are correlated with chemical substitution. This allows these systems be controllably tuned toward (and possibly into)...
Topological superconductivity is a long-sought state of matter in bulk materials, and the odd-parity superconductor UTe2 prime candidate. The recent observation field-trainable spontaneous Kerr signal at onset provides strong evidence that superconducting order parameter multicomponent breaks time-reversal symmetry. Here, we perform effect measurements on number samples—grown via both chemical vapor transport molten-salt-flux methods—that show single transition between 1.6 K 2.1 K. Our...
We report on the pressure evolution of Fermi surface topology Weyl semimetal NbP, probed by Shubnikov--de Haas oscillations in magnetoresistance combined with ab initio calculations band structure. Although we observe a drastic effect amplitudes quantum oscillations, frequencies only exhibit weak dependence up to 2.8 GPa. The pressure-induced variations oscillation are consistent our band-structure calculations. Furthermore, can relate changes small modifications shape surface. Our findings...
Topological semimetals are three dimensional materials with symmetry-protected massless bulk excitations. As a special case, Weyl nodal-line realized in either having no inversion or broken time-reversal symmetry and feature nodal lines. The 111-family of materials, LaNiSi, LaPtSi LaPtGe (all lacking symmetry), belong to this class. Here, by combining muon-spin rotation relaxation thermodynamic measurements, we find that these exhibit fully-gapped superconducting ground state, while...
The Weyl semimetal NbP exhibits an extremely large magnetoresistance and ultra-high mobility. originates from a combination of the nearly perfect compensation between electron- hole-type charge carriers high mobility, which is relevant to topological band structure. In this work we report on temperature- field-dependent thermopower thermal conductivity experiments NbP. Additionally, carried out complementary heat capacity, magnetization, electrical resistivity measurements. We found giant...
Our studies evidence an anisotropic magnetic order below $T_N = 32$~K. Susceptibility data in small fields of about 1~T reveal antiferromagnetic (AFM) for $H \perp c$, whereas \parallel c$ the are reminiscent a field-induced ferromagnetic (FM) structure. At low temperatures and field-dependent magnetization AC susceptibility metamagnetic transition at $H^+ 5$~T, which is absent c$. We assign this to from planar cycloidal spin structure fan-like arrangement above $H^+$. A fully FM polarized...
We report on the pressure evolution of giant anomalous Hall effect (AHE) in chiral antiferromagnet Mn$_3$Ge. The AHE originating from non-vanishing Berry curvature Mn$_3$Ge can be continuously tuned by application hydrostatic pressure. At room temperature, signal changes sign as a function and vanishes completely at $p=1.53$ GPa. Even though conductivity upon increasing pressure, room-temperature saturation value 23 ${\rm \Omega^{-1}cm^{-1}}$ 2.85 GPa is remarkably high comparable to ambient...
Noncentrosymmetric Ce${}_{3}$Bi${}_{4}$Pd${}_{3}$ has recently attracted tremendous attention as a strongly correlated topological semimetal candidate. Conflicting experimental results, however, argue for either Weyl Kondo semimetallic or narrow-gap insulating ground state. Using electrical transport measurements on bulk crystals and microstructure devices under hydrostatic pressure, the authors show that exhibits The results provide important evidence state of sought-after candidate shed...
We report neutron scattering, pressure-dependent AC calorimetry, and magnetic susceptibility measurements of triangular lattice NaYbSe$_2$. observe a continuum which is reproduced by matrix product simulations, no phase transition detected in any bulk measurements. Comparison to heat capacity simulations suggest the material within Heisenberg spin liquid phase. Susceptibility shows significant 23~mK downturn, indicating gap spectrum. The combination with detectable order, comparison...
Cerium-based compounds crystallizing in the cubic Ce${}_{3}{X}_{4}\phantom{\rule{0}{0ex}}{T}_{3}$ ($X$=Bi, Sb and $T$=transition metal) structure present a wide variety of semiconducting ground states ranging from conventional band gap Ce${}_{3}$Sb${}_{4}$Au${}_{3}$ to prototypical Kondo insulating behavior Ce${}_{3}$Bi${}_{4}$Pt${}_{3}$. The variation physical properties among members stems delicate interplay between crystal lattice, electron filling, hybridization $f$ electrons conduction...
Abstract We investigated the anisotropic magnetic properties of CePd 2 As by magnetic, thermal and electrical transport studies. X-ray diffraction confirmed tetragonal ThCr Si -type structure high-quality single crystals. Magnetisation susceptibility data taken along different crystallographic directions evidence a huge crystalline electric field (CEF) induced Ising-type magneto-crystalline anisotropy with large c -axis moment small in-plane at low temperature. A detailed CEF analysis based...
Competing ground states often lead to the emergence of novel unconventional phases. The presence magnetic frustration in such materials brings about additional complexity. Here, authors present a comprehensive study on ground-state properties LuFe${}_{4}$Ge${}_{2}$, ternary intermetallic compound with and quasi-one-dimensional structure, elucidating interplay structure magnetism. In contrast well-studied two-dimensional iron pnictides competing exchange interactions, LuFe${}_{4}$Ge${}_{2}$...
We report in-plane electrical resistivity studies of CeCuBi2 and LaCuBi2 single crystals under applied pressure. At ambient pressure, is a c-axis Ising antiferromagnet with transition temperature [Formula: see text] K. In magnetic field along the at K spin-flop takes place T. Applying pressure on suppresses T N slow rate. extrapolates to zero GPa. The critical displays maximum 6.8 low temperatures, zero-resistance superconducting state emerges upon application external having c 7 2.6 GPa in...
We investigated the pressure evolution of electrical transport in almost compensated Weyl semimetal TaP. In addition, we obtained information on modifications Fermi-surface topology with from analysis pronounced Shubnikov-de Haas (SdH) quantum oscillations present Hall-effect and magnetoresistance data. The simultaneous Hall longitudinal conductivity data a two-band model revealed an only weak decrease electron- hole charge-carrier densities up to 1.2 GPa, while mobilities are essentially...
We explore the effect of Ga substitution on physical properties single crystals ${\mathrm{Ce}}_{2}{\mathrm{RhIn}}_{8}$ through measurements temperature-dependent specific heat, magnetic susceptibility, and electrical resistivity. Our data ${\mathrm{Ce}}_{2}{\mathrm{RhIn}}_{8\ensuremath{-}x}{\mathrm{Ga}}_{x}$, reveal a monotonic decrease antiferromagnetic transition temperature from ${T}_{N}=2.77$ K for parent compound to ${T}_{N}$ = 1.96 highest concentration achieved ($x=0.55$). To...
We report a study of the structural, magnetic, transport, and thermodynamic properties polycrystalline samples ${\mathrm{CeRhC}}_{2}$ ${\mathrm{LaRhC}}_{2}$. crystallizes in tetragonal structure with space group $P{4}_{1}$, it orders antiferromagnetically below ${T}_{\text{N1}}\ensuremath{\approx}1.8\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Powder neutron diffraction measurements reveal chiral magnetic single propagation vector ${Q}_{m}=(1/2,1/2,0.228(5))$, indicating an antiferromagnetic...
The Fe sublattice in the compound ${\mathrm{ZrFe}}_{4}{\mathrm{Si}}_{2}$ features geometrical frustration and quasi-one-dimensionality. We therefore investigated magnetic behavior its evolution upon substituting Ge for Si under application of hydrostatic pressure using structural, magnetic, thermodynamic, electrical-transport probes. Magnetic measurements reveal that holds paramagnetic moments with an effective moment ${\ensuremath{\mu}}_{\mathrm{eff}}=2.18{\ensuremath{\mu}}_{B}$. At low...
We investigated the effect of application hydrostatic pressure on charge-density wave (CDW) state in Lu(Pt1−xPdx)2In by electrical-resistivity measurements. In Lu(Pt0.7Pd0.3)2In we find an increase CDW transition temperature upon pressure, which is not expected based simple volume arguments, but line with results a theoretical work Kim et al. [Phys. Rev. Lett. 125, 157001 (2020)]. Combining experimental and suggests existence quantum critical point stoichiometric LuPd2In around p ≈ 20 GPa.
LuFe$_4$Ge$_2$ crystallizes in the ZrFe$_4$Si$_2$-type structure, hosting chains of Fe-tetrahedra giving rise to geometric frustration and low-dimensionality. The compound orders antiferromagnetically at around 36 K accompanied by a simultaneous structural transition from tetragonal an orthorhombic phase. hydrostatic pressure dependence magnetic transitions is investigated using electrical-transport, ac magnetic-susceptibility, calorimetry, M$\ddot{\rm o}$ssbauer, muon-spin relaxation...