Ultrafast Relaxation Dynamics of Photoexcited Dirac Fermion in The Three Dimensional Dirac Semimetal Cadmium Arsenide

Abstract

Three dimensional (3D) Dirac semimetals which can be seen as 3D analogues of graphene have attracted enormous interests in research recently. In order to apply these ultrahigh-mobility materials in future electronic/optoelectronic devices, it is crucial to understand the relaxation dynamics of photoexcited carriers and their coupling with lattice. In this work, we report ultrafast transient reflection measurements of the photoexcited carrier dynamics in cadmium arsenide (Cd3As2), which is one of the most stable Dirac semimetals that have been confirmed experimentally. By using low energy probe photon of 0.3 eV, we probed the dynamics of the photoexcited carriers that are Dirac-Fermi-like approaching the Dirac point. We systematically studied the transient reflection on bulk and nanoplate samples that have different doping intensities by tuning the probe wavelength, pump power and lattice temperature, and find that the dynamical evolution of carrier distributions can be retrieved qualitatively by using a two-temperature model. This result is very similar to that of graphene, but the carrier cooling through the optical phonon couplings is slower and lasts over larger electron temperature range because the optical phonon energies in Cd3As2 are much lower than those in graphene.

References in corpus (15)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Intrinsic and Extrinsic Performance Limits of Graphene Devices on SiO2
• Photo-excitation Cascade and Multiple Carrier Generation in Graphene
• Quantum transport evidence for a three-dimensional Dirac semimetal phase in Cd3As2
• Linear magnetoresistance caused by mobility fluctuations in the n-doped Cd3As2
• Dynamical Evolution of Anisotropic Response in Black Phosphorus under Ultrafast Photoexcitation
• Quasiparticle Dynamics in Reshaped Helical Dirac Cone of Topological Insulators
• Population Inversion in Monolayer and Bilayer Graphene
• Transient reflectance of photoexcited Cd${}_3$As${}_2$
• Dirac semimetals $A_{3}Bi$ ($A$=Na,K,Rb) as $Z_2$ Weyl semimetals
• Surface Fermi arcs in $Z_2$ Weyl semimetals $A_{3}Bi$ (A=Na, K, Rb)

Cited by in corpus (14)

• Ultrafast Broadband Photodetectors based on Three-dimensional Dirac Semimetal Cd3As2
• Topological Semimetal Nanostructures: From Properties to Topotronics
• Ultrafast photothermoelectric effect in Dirac semimetallic Cd3As2 revealed by terahertz emission
• Similar ultrafast dynamics of several dissimilar Dirac and Weyl semimetals
• Experimental Progress on Layered Topological Semimetals
• Terahertz Polarization Conversion from Optical Dichroism in a Topological Dirac Semimetal
• Population inversion and Dirac fermion cooling in 3D Dirac semimetal Cd${}_3$As${}_2$
• Tracking ultrafast change of multiterahertz broadband response functions in a photoexcited Dirac semimetal Cd${}_3$As${}_2$ thin film
• Ultrafast Spectroscopy of Dirac Semimetal Cd3As2 under Pressure
• Electron dynamics in a three-dimensional Brillouin zone analysed by machine learning
• Ultrafast carrier dynamics throughout the three-dimensional Brillouin zone of the Weyl semimetal PtBi${}_2$
• Ultrafast photoinduced phase transition in the antiferromagnetic Dirac semimetal EuAgAs
• Anomalous electronic energy relaxation and soft phonons in the Dirac semimetal Cd${}_3$As${}_2$
• Research on topological materials using ultrafast spectroscopy