Field-angle dependence of sound velocity in the Weyl semimetal TaAs

Abstract

The elastic modulus $c_{44}$ of a single crystal of the Weyl semimetal TaAs was investigated by measuring relative changes in the sound velocity under application of a magnetic field up to 10 T. Using an ultrasonic pulsed-echo technique, we studied the shear response of the crystal when the angle between the sound wave propagation and the magnetic field is changed. We observe a broken tetragonal symmetry at fields above 6 T, an anisotropy that is likely related to a longitudinal negative magnetoresistance and therefore might provide evidence of the chiral anomaly, one of the main topological signatures of this class of materials. We also observe quantum oscillations in the sound velocity whose frequencies vary with magnetic field orientation. A fan diagram of Landau level indices reveals topological and trivial Berry phases, depending on the field orientation, indicating a sensitivity to different Fermi surface pockets that do or do not enclose Weyl nodes respectively.

References in corpus (24)

• Discovery of a Weyl Fermion Semimetal and Topological Fermi Arcs
• Experimental discovery of Weyl semimetal TaAs
• Observation of the chiral anomaly induced negative magneto-resistance in 3D Weyl semi-metal TaAs
• Negative magnetoresistance without well-defined chirality in the Weyl semimetal TaP
• Signatures of the Adler-Bell-Jackiw chiral anomaly in a Weyl Fermion semimetal
• Recent developments in transport phenomena in Weyl semimetals
• The chiral anomaly and thermopower of Weyl fermions in the half-Heusler GdPtBi
• Giant negative magnetoresistance induced by the chiral anomaly in individual Cd3As2 nanowires
• Transport evidence for Fermi-arc mediated chirality transfer in the Dirac semimetal Cd${}_3$As${}_2$
• Experimental observation of optical Weyl points
• Phase analysis of quantum oscillations in graphite
• Chiral anomaly from strain-induced gauge fields in Dirac and Weyl semimetals
• On the search for the chiral anomaly in Weyl semimetals: The negative longitudinal magnetoresistance
• Fermi arc topology and interconnectivity in Weyl fermion semimetals TaAs, TaP, NbAs, and NbP
• Magneto-transport phenomena related to the chiral anomaly in Weyl semimetals
• Chiral Quasiparticles at the Fermi Surface of the Weyl Semimetal TaAs
• Quantum limit transport and destruction of the Weyl nodes in TaAs
• Quantum oscillations and the Fermi-surface topology of the Weyl semimetal NbP
• Magnetic torque anomaly in the quantum limit of the Weyl semi-metal NbAs
• Signatures of the chiral anomaly in phonon dynamics
• Detecting Chiral Magnetic Effect by Lattice Dynamics
• Pressure tuning the Fermi-surface topology of the Weyl semimetal NbP
• Influence of Landau levels in the phonon dispersion of Weyl semimetals
• Berry Phase in Cuprate Superconductors

Cited by in corpus (11)

• Phonon helicity induced by electronic Berry curvature in Dirac materials
• Phonon magnetochiral effect of band-geometric origin in Weyl semimetals
• Infinite Berry Curvature of Weyl Fermi Arcs
• Phonon-limited Transport and Fermi Arc Lifetime in Weyl Semimetals
• Anomalous sound attenuation in Weyl semimetals in magnetic and pseudomagnetic fields
• Propagation of longitudinal acoustic phonons in ZrTe${}_5$ exposed to a quantizing magnetic field
• Detection of relativistic fermions in Weyl semimetal TaAs by magnetostriction measurements
• Weyl nodes close to the Fermi energy in NbAs
• Electric and chiral response to a pseudoelectric field in Weyl materials
• Axionic Acoustic Phonons from Weyl Semimetals
• Search for magnetoacoustic quantum oscillations in the insulating phase of YbB${}_{12}$