A5035434685- Iron-based superconductors research
- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- Graphene research and applications
- Quantum and electron transport phenomena
- Nuclear materials and radiation effects
- Crystallization and Solubility Studies
- Organic and Molecular Conductors Research
- X-ray Diffraction in Crystallography
- Quantum Mechanics and Non-Hermitian Physics
- Magnetic Properties of Alloys
Helmholtz-Zentrum Dresden-Rossendorf
2016-2024
TU Dresden
2017-2022
Complexity and Topology in Quantum Matter
2022
Weyl and Dirac fermions have created much attention in condensed matter physics materials science. Recently, several additional distinct types of been predicted. Here, we report ultra-high electrical conductivity MoP at low temperature, which has recently established as a triple point Fermion material. Here show that the resistivity is 6 n-ohm cm 2 K with large mean free path 11 microns. de Haas-van Alphen oscillations reveal spin splitting Fermi surfaces. In contrast to noble metals similar...
Non-symmorphic chiral topological crystals host exotic multifold fermions, and their associated Fermi arcs helically wrap around expand throughout the Brillouin zone between high-symmetry center surface-corner momenta. However, Fermi-arc splitting realization of theoretically proposed maximal Chern number rely heavily on spin-orbit coupling (SOC) strength. In present work, we investigate states a new crystal, PtGa, which has strongest SOC among all reported to date. With comprehensive...
The potential spin-triplet heavy-fermion superconductor UTe
Physical properties of a pyrohafnate compound Pr2Hf2O7 have been investigated by ac magnetic susceptibility \chi_ ac(T), dc \chi(T), isothermal magnetization M(H) and heat capacity C_p(T) measurements on polycrystalline as well single crystal samples combined with high-resolution synchrotron x-ray diffraction (XRD) for structural characterization inelastic neutron scattering (INS) to determine the field energy level scheme wave functions. Synchrotron XRD data confirm ordered cubic pyrochlore...
We report the observation of magnetic domains in exotic, antiferromagnetically ordered all-in-all-out state ${\mathrm{Nd}}_{2}{\mathrm{Zr}}_{2}{\mathrm{O}}_{7}$, induced by spin canting. The can be realized Ising-like spins on a pyrochlore lattice and is established ${\mathrm{Nd}}_{2}{\mathrm{Zr}}_{2}{\mathrm{O}}_{7}$ below 0.31 K for external fields up to 0.14 T. Two different arrangements fulfill this configuration which leads possibility domains. domain structure controlled an field...
We report the physical properties of ${\mathrm{Tb}}_{2}{\mathrm{Hf}}_{2}{\mathrm{O}}_{7}$ based on ac magnetic susceptibility ${\ensuremath{\chi}}_{\mathrm{ac}}(T)$, dc $\ensuremath{\chi}(T)$, isothermal magnetization $M(H)$, and heat capacity ${C}_{\mathrm{p}}(T)$ measurements combined with muon spin relaxation ($\ensuremath{\mu}\mathrm{SR}$) neutron powder diffraction measurements. No evidence for long-range order is found down to 0.1 K. However, ${\ensuremath{\chi}}_{\mathrm{ac}}(T)$ data...
Magnetic remanence---found in bar magnets or magnetic storage devices---is probably the oldest and most ubiquitous phenomenon underpinning technological applications of magnetism. It is a macroscopic nonequilibrium phenomenon: A remanent magnetization appears when field applied to an initially unmagnetized ferromagnet, then taken away. Here, we present inverted hysteresis loop pyrochlore compound ${\mathrm{Nd}}_{2}{\mathrm{Hf}}_{2}{\mathrm{O}}_{7}$: The points direction opposite field. This...
In insulators, the longitudinal resistivity becomes infinitely large at zero temperature. For classic Hall conductivity same time. However, there are special systems, such as two-dimensional quantum isolators, in which a more complex scenario is observed high magnetic fields. Here, we report experimental evidence for quasi-quantized insulator limit of three-dimensional semimetal SrSi2. Our measurements reveal field-range, diverges with decreasing temperature, while approaches value that...
The transversal magnetoresistance associated with the semimetal ${\mathrm{TaAs}}_{2}$ shows a parabolic field dependence that rises unrestrictedly to 2800 at 14 T and 1.8 K. Here, we report results of comprehensive quantum-oscillation study. Angular-dependent de Haas--van Alphen (dHvA) data were obtained method cantilever-torque magnetometry. These compared density-functional theory calculations, which predict Fermi surface two kinds electron pockets, as well types hole pockets. Only pockets...
We report a comprehensive de Haas--van Alphen (dHvA) study of the heavy-fermion material CeRhIn$_5$ in magnetic fields up to 70~T. Several dHvA frequencies gradually emerge at high as result breakdown. Among them is thermodynamically important $\beta_1$ branch, which has not been observed so far. Comparison our angule-dependent spectra with those non-$4f$ compound LaRhIn$_5$ and band-structure calculations evidences that Ce $4f$ electrons remain localized over whole field range. This rules...
We present a comprehensive ultrasound study of the prototypical heavy-fermion material CeRhIn$_5$, examining origin enigmatic 30 T transition. For field applied at 2$^\circ$ from $c$ axis, we observed two sharp anomalies in sound velocity, $B_m \approx$ 20 and $B^* T, all symmetry-breaking modes low temperatures. The lower-field anomaly corresponds to well-known first-order metamagnetic incommensurate-to-commensurate higher-field takes place where an electronic-nematic transition was...
We report on magnetic-torque and resistivity measurements of the heavy-fermion compound ${\mathrm{CeCoIn}}_{5}$ in static magnetic fields up to 36 T temperatures down 50 mK. While quantum oscillations de Haas--van Alphen (dHvA) as well Shubnikov--de Haas (SdH) effect confirm previously reported Fermi surfaces, an analysis field dependence reveals two anomalous features. The first is seen at about 22 a sharp anomaly for current applied along $a$ direction. second appears nonmonotonic...
We report that the lattice constant of Dy$_2$Ge$_{2-x}$Si$_x$O$_7$ ($x=0, 0.02, 0.08, 0.125$) can be systematically reduced by substituting non-magnetic germanium ion in cubic pyrochlore oxide with silicon. A multi-anvil high-pressure synthesis was performed up to 16 GPa and 1100 $^\circ$C obtain polycrystalline samples a solid-state reaction. Measurements magnetization, ac susceptibility, heat capacity reveal typical signatures spin-ice phase. From temperature shift peaks, observed...
PtGa is a topological semimetal with giant spin-split Fermi arcs. Here, we report on angular-dependent de Haas-van Alphen (dHvA) measurements combined band-structure calculations to elucidate the details of bulk surface PtGa. The strong spin-orbit coupling leads eight bands crossing energy that form multitude surfaces closed extremal orbits and results in very rich dHvA spectra. large number experimentally observed frequencies make assignment equally calculated challenging. Nevertheless,...
The thermodynamics in spin-ice systems are governed by emergent magnetic monopole excitations and, until now, the creation of a pair these topological defects was associated with one specific pair-creation energy. Here, we show that electric dipole moments inherent to monopoles lift degeneracy their process and lead splitting We consider this finding extend model relaxation an interaction theoretically estimated order magnitude leads which can explain controversially discussed discrepancies...
The noncentrosymmetric superconductor $\ensuremath{\alpha}$-PdBi is a candidate material for the realization of topological superconductivity. Here, we present detailed de Haas--van Alphen (dHvA) study together with band-structure calculations within framework density functional theory. rich dHvA spectra are manifestation 13 bands that cross Fermi energy ${E}_{F}$. We find excellent agreement between calculated and experimentally observed frequencies moderately enhanced effective masses. One...
Abstract The potential spin-triplet heavy-fermion superconductor UTe 2 exhibits signatures of multiple distinct superconducting phases. For field aligned along the b axis a metamagnetic transition occurs at μ 0 H m ≈ 35 T. It is associated with spin reorientation inducing magnetic fluctuations that may be beneficial for field-enhanced superconductivity surviving up to . Once tilted away from towards c axis, re-entrant phase emerges just above (θ). However, under pressure this detaches Hm. In...
The potential spin-triplet heavy-fermion superconductor UTe$_2$ exhibits signatures of multiple distinct superconducting phases. For field aligned along the $b$ axis, a metamagnetic transition occurs at $\mu_0 H_\mathrm{m}\approx35\,$T. It is associated with magnetic fluctuations that may be beneficial for field-reinforced superconductivity surviving up to $H_\mathrm{m}$. Once tilted away from towards $c$ reentrant phase emerges just above In order better understand this remarkably...