Evidence for Half-Metallicity in n-type HgCr2Se4

Abstract

High quality HgCr${}_2$Se${}_4$ single crystals have been investigated by magnetization, electron transport and Andreev reflection spectroscopy. In the ferromagnetic ground state, the saturation magnetic moment of each unit cell corresponds to an integer number of electron spins (3 ${\mu }_B$/Cr${}^{3+}$), and the Hall effect measurements suggest n-type charge carriers. Spin polarizations as high as $97\%$ were obtained from fits of the differential conductance spectra of HgCr${}_2$Se${}_4$/Pb junctions with the modified Blonder-Tinkham-Klapwijk (BTK) theory. The temperature and bias-voltage dependencies of the sub-gap conductance are consistent with recent theoretical calculations based on spin active scatterings at a superconductor/half metal interface. Our results suggest that n-HgCr${}_2$Se${}_4$ is a half metal, in agreement with theoretical calculations that also predict undoped HgCr${}_2$Se${}_4$ is a magnetic Weyl semimetal.

6 pages, 4 figures, to appear in PRL

References in corpus (11)

• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Discovery of a Weyl Fermion Semimetal and Topological Fermi Arcs
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Experimental discovery of Weyl semimetal TaAs
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Half-metallic ferromagnets: From band structure to many-body effects
• A spin triplet supercurrent through the half-metallic ferromagnet CrO2
• Andreev Reflection in Heavy-Fermion Superconductors and Order Parameter Symmetry in CeCoIn_5
• Quantum limit of the triplet proximity effect in half-metal - superconductor junctions
• Is CrO${}_2$ Fully Spin-Polarized? - Analysis of Andreev Spectra and Excess Current
• Dephasing-enabled triplet Andreev conductance

Cited by in corpus (29)

• Quantum anomalous Hall effect and related topological electronic states
• Negative Magnetoresistance in Dirac Semimetal Cd3As2
• Discovery of Weyl fermion semimetals and topological Fermi arc states
• Topological Semimetals Predicted from First-principles Calculations
• Arc-tunable Weyl Fermion metallic state in Mo${}_x$W${}_{1-x}$Te${}_2$
• Weyl, Dirac and high-fold chiral fermions in topological quantum materials
• Quantum Transport in Topological Semimetals under Magnetic Fields
• Understanding topological phase transition in transition metal dichalcogenides
• The study of magnetic topological semimetals by first principles calculations
• Linear magnetoconductivity in an intrinsic topological Weyl semimetal
• Thermoelectric transport in double-Weyl semimetals
• Emergent Electromagnetic Induction and Adiabatic Charge Pumping in Weyl Semimetals
• Half-metallic Ferromagnets, Spin Gapless Semiconductors, and Topological Semimetals Based on Heusler Alloys
• Fermi arc plasmons in Weyl semimetals
• Proposal for detecting nodal-line semimetal surface-states with resonant spin-flipped reflection
• Detecting monopole charge in Weyl semimetals via quantum interference transport
• Collective modes in multi-Weyl semimetals
• Half-Metallic Ferromagnets and Spin Gapless Semiconductors
• Chiral magnetic effect in the absence of Weyl node
• Unconventional temperature dependence of the anomalous Hall effect in HgCr2Se4
• Spin correlations and colossal magnetoresistance in HgCr${}_2$Se${}_4$
• Magnetic competition induced colossal magnetoresistance in n-type HgCr2Se4 under high pressures
• Quantum phase transition and unusual critical behavior in multi-Weyl semimetals
• Topological Phase Transitions and a Two-Dimensional Weyl Superconductor in a Half-Metal/Superconductor Heterostructure
• Momentum-Space Electromagnetic Induction in Weyl Semimetals
• Andreev bound states in superconductor/ferromagnet point contact Andreev reflection spectra
• Electronic Origin of Half-metal to Semiconductor Transition and Colossal Magnetoresistance in Spinel HgCr2Se4
• Semiconducting Electronic Structure of the Ferromagnetic Spinel $\mathbf{Hg}{\mathbf{Cr}}_2{\mathbf{Se}}_4$ Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy
• Superconductivity in multi-Weyl semimetals: Conditions for the coexistence of topological and conventional phases