Analysis of the unconventional chiral fermions in a non-centrosymmetric chiral crystal $\text{PtAl}$

Abstract

Symmetry-protected non-trivial states in chiral topological materials hold immense potential for fundamental science and technological advances. Here, we report electrical transport, quantum oscillations, and electronic structure results of a single crystal of chiral quantum material $\mathrm{PtAl}$. Based on the de Haas-van Alphen (dHvA) oscillations, we show that the smallest Fermi pocket ($\alpha$) possesses a non-trivial Berry phase $1.16$$\pi$. The band associated with this Fermi pocket carries a linear energy dispersion over a substantial energy window of $\sim$700 meV that is further consistent with the calculated optical conductivity. First-principles calculations unfold that $\mathrm{PtAl}$ is a higher-fold chiral fermion semimetal where structural chirality drives the chiral fermions to lie at the high-symmetry $\Gamma$ and $R$ points of the cubic Brillouin zone. In the absence of spin-orbit coupling, the band crossings at $\Gamma$ and $\mathrm{R}$ points are three- and four-fold degenerate with a chiral charge of $-2$ and $+2$, respectively. The inclusion of spin-orbit coupling transforms these crossing points into four- and six-fold degenerate points with a chiral charge of $-4$ and $+4$. Nontrivial surface states on the $(001)$ plane connect the bulk projected chiral points through the long helical Fermi arcs that spread over the entire Brillouin zone.

References in corpus (44)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions
• Classification of topological quantum matter with symmetries
• WannierTools: An open-source software package for novel topological materials
• Discovery of a Three-dimensional Topological Dirac Semimetal, Na3Bi
• Quantum ESPRESSO toward the exascale
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Three Dimensional Dirac Semimetal and Quantum Transports in Cd3As2
• Theoretical Discovery/Prediction: Weyl Semimetal states in the TaAs material (TaAs, NbAs, NbP, TaP) class
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Beyond Dirac and Weyl fermions: Unconventional quasiparticles in conventional crystals
• The (High Quality) Topological Materials In The World
• Observation of Weyl nodes in TaAs
• Catalogue of Topological Electronic Materials
• Quantized circular photogalvanic effect in Weyl semimetals
• Symmetry Protected Topological phases of Quantum Matter
• Giant anisotropic nonlinear optical response in transition metal monopnictide Weyl semimetals
• Wien2wannier: From linearized augmented plane waves to maximally localized Wannier functions
• Topological quantum properties of chiral crystals
• Experimental discovery of a topological Weyl semimetal state in TaP
• Direct optical detection of Weyl fermion chirality in a topological semimetal
• Large Fermi Arcs in Unconventional Weyl Semimetal RhSi
• Experimental Observation of Three-Component 'New Fermions' in Topological Semimetal MoP
• Arc-tunable Weyl Fermion metallic state in Mo${}_x$W${}_{1-x}$Te${}_2$
• Topological Semimetals from first-principles
• Observation of Topological Photocurrents in the Chiral Weyl Semimetal RhSi
• Topological surface states and Fermi arcs of the noncentrosymmetric Weyl semimetals TaAs, TaP, NbAs, and NbP
• Chiral Optical Response of Multifold Fermions
• Observation and control of maximal Chern numbers in a chiral topological semimetal
• Ideal Weyl semimetals in the chalcopyrites CuTlSe2, AgTlTe2, AuTlTe2 and ZnPbAs2
• Three-component fermions with surface Fermi arcs in topological semimetal tungsten carbide
• Bulk crystal growth and electronic characterization of the 3D Dirac Semimetal Na3Bi
• Linear and nonlinear optical responses in the chiral multifold semimetal RhSi
• Multifold nodal points in magnetic materials
• Observation of giant spin-split Fermi-arc with maximal Chern number in the chiral topological semimetal PtGa
• Optical signatures of multifold fermions in the chiral topological semimetal CoSi
• Chiral fermion reversal in chiral crystals
• Linear optical conductivity of chiral multifold fermions
• Direct observation of handedness-dependent quasiparticle interference in the two enantiomers of topological chiral semimetal PdGa
• Optical conductivity of multifold fermions: the case of RhSi
• Topology of Triple-Point Metals
• Prediction of three-fold fermions in a nearly-ideal Dirac semimetal BaAgAs
• Broadband optical conductivity of the chiral multifold semimetal PdGa
• Fermi surface studies of a non-trivial topological compound YSi

Cited by in corpus (1)

• Ultrafast Carrier Relaxation and Second Harmonic Generation in a Higher-Fold Weyl Fermionic System PtAl