title: Electron energy relaxation under terahertz excitation in (Cd1-xZnx)3As2Dirac semimetals.
abstract: We demonstrate that measurements of the photo-electromagnetic effect using terahertz laser radiation provide an argument for the existence of highly conductive surface electron states with a spin texture in Dirac semimetals (Cd1-xZnx)3As2. We performed a study on a range of (Cd1-xZnx)3As2mixed crystals undergoing a transition from the Dirac semimetal phase with an inverse electron energy spectrum to trivial a semiconductor with a direct spectrum in the crystal bulk by varying the compositionx. We show that for the Dirac semimetal phase, the photo-electromagnetic effect amplitude is defined by the number of incident radiation quanta, whereas for the trivial semiconductor phase, it depends on the laser pulse power, irrespective of wavelength. We assume that such behavior is attributed to a strong damping of the interelectron interaction in the Dirac semimetal phase compared to the trivial semiconductor, which may be due to the formation of surface electron states with a spin texture in Dirac semimetals.
authors.affiliation: Physics Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.2, 119991 Moscow, Russia.
authors.forename: Alexandra V
authors.initials: AV
authors.lastname: Galeeva
authors.affiliation: Physics Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.2, 119991 Moscow, Russia.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Krylov
authors.affiliation: Physics Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.2, 119991 Moscow, Russia.
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Drozdov
authors.affiliation: Kursk Construction College, Sovetskaya str. 14, 305016 Kursk, Russia.
authors.forename: Anatoly F
authors.initials: AF
authors.lastname: Knjazev
authors.affiliation: South-West State University, 50 Let Oktyabrya str. 94, 305040 Kursk, Russia.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Kochura
authors.affiliation: South-West State University, 50 Let Oktyabrya str. 94, 305040 Kursk, Russia.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Kuzmenko
authors.affiliation: Belgorod National Research University, Pobedy str. 85, 308015 Belgorod, Russia.
authors.forename: Vasily S
authors.initials: VS
authors.lastname: Zakhvalinskii
authors.affiliation: Faculty of Physics, University of Regensburg, Universitaetstr. 31, 93053 Regensburg, Germany.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Danilov
authors.affiliation: Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.3, 119991 Moscow, Russia.
authors.forename: Ludmila I
authors.initials: LI
authors.lastname: Ryabova
authors.affiliation: Physics Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.2, 119991 Moscow, Russia.
authors.forename: Dmitry R
authors.initials: DR
authors.lastname: Khokhlov
keywords: Dirac semimetal; photo-electromagnetic effect; terahertz radiation; topological insulator