Similar ultrafast dynamics of several dissimilar Dirac and Weyl semimetals

Abstract

Recent years have seen the rapid discovery of solids whose low-energy electrons have a massless, linear dispersion, such as Weyl, line-node, and Dirac semimetals. The remarkable optical properties predicted in these materials show their versatile potential for optoelectronic uses. However, little is known of their response in the picoseconds after absorbing a photon. Here we measure the ultrafast dynamics of four materials that share non-trivial band structure topology but that differ chemically, structurally, and in their low-energy band structures: ZrSiS, which hosts a Dirac line node and Dirac points; TaAs and NbP, which are Weyl semimetals; and Sr${}_{1-y}$Mn${}_{1-z}$Sb${}_2$, in which Dirac fermions coexist with broken time-reversal symmetry. After photoexcitation by a short pulse, all four relax in two stages, first sub-picosecond, and then few-picosecond. Their rapid relaxation suggests that these and related materials may be suited for optical switches and fast infrared detectors. The complex change of refractive index shows that photoexcited carrier populations persist for a few picoseconds.

References in corpus (14)

• Titanic Magnetoresistance in WTe2
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3
• Photocurrents in Weyl semimetals
• Ultrafast Broadband Photodetectors based on Three-dimensional Dirac Semimetal Cd3As2
• Chiral anomaly and optical absorption in Weyl semimetals
• Electron scattering in tantalum monoarsenide
• Tunable point nodes from line node semimetals via application of light
• Ultrafast Relaxation Dynamics of Photoexcited Dirac Fermion in The Three Dimensional Dirac Semimetal Cadmium Arsenide
• Population Inversion in Monolayer and Bilayer Graphene
• Transient reflectance of photoexcited Cd${}_3$As${}_2$
• Free-carrier relaxation and lattice heating in photoexcited bismuth thin films
• Ultra-broadband photodetection of Weyl semimetal TaAs up to infrared 10 μm range at room temperature
• Ultrafast Electronic Dynamics of a Weyl Semimetal MoTe${}_2$ Revealed by Time and Angle Resolved Photoemission Spectroscopy

Cited by in corpus (10)

• Topological frequency conversion in Weyl semimetals
• High-harmonic generation in semi-Dirac and Weyl semimetals with broken time-reversal symmetry: Exploring merging of Weyl nodes
• Quasiparticle interference observation of the topologically non-trivial drumhead surface state in ZrSiTe
• Ultrafast carrier dynamics throughout the three-dimensional Brillouin zone of the Weyl semimetal PtBi${}_2$
• Electron dynamics in a three-dimensional Brillouin zone analysed by machine learning
• Coherent phonon and unconventional carriers in the magnetic kagome metal Fe${}_3$Sn${}_2$
• Anomalous electronic energy relaxation and soft phonons in the Dirac semimetal Cd${}_3$As${}_2$
• Topological frequency conversion in rhombohedral multilayer graphene
• Real-space visualization of quasiparticle dephasing near the Planckian limit in the Dirac line node material ZrSiS
• Research on topological materials using ultrafast spectroscopy