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0LOW-TEMPERATURE NONPARABOLIC MAGNETORESISTANCE IN HoTe3
Voropaev D.M.12, Cohn I.A.13, Tyumentsev M.M.13, Grigoriev P.D.4, Zaitsev-Zotov S.V.1'3, Pachoud E.5, Hadj-Azzem A., Monceau P. 5
xKotel'nikov Institute ofRadioengineering and Electronics of RAS, Moscow, Russia 2Moscow Institute of Physics and Technology, Dolgoprudny, Russia 3Higher School of Economics, Moscow, Russia 4 L.D. Landau Institute for Theoretical Physics, Chernogolovka, Russia
5 Université Grenoble Alpes, CNRS, Grenoble INP, Institut NEEL, Grenoble, France
Electron-phonon interaction often leads to breaking of the symmetry of ground states in solids, for instance to the development of a charge density wave (CDW). The CDW ground state is characterized by the spatial modulation of electron density p<x cos(Qcdw r + 0) and by the periodic lattice distortion with the same wave vector Qcdw, causing the opening of a gap in the electronic spectrum [1]. In some cases, the ground state arising due to the formation of CDW may be semimetallic, if electronic and hole pockets remain on the Fermi surface. Quasi-two-dimensional (q-2D) tritelluride HoTe3 is just such a material. This compound has an orthorhombic crystal structure (Cmcm space group) and consists of double Te planes separated by corrugated RTe planes; b-axis is perpendicular to the Te planes. HoTe3 demonstrates the transition to a state with a CDW with Qcdw1 = (0, 0; ~ 2c*/7) incommensurable with the lattice at Tp1 = 283 K. A second CDW transition with Qcdw2 = (~2a*/7, 0, 0) perpendicular to Qcdw1 develops at Tp2 = 110 K.
Previously, transverse magnetoresistance (MR) in this compound was studied at temperatures > 20 K for only one of the directions [2]. It was found that with a decrease in temperature, the MR of HoTe3 gradually changes from quadratic to linear. Here we present our results of studying the transverse MR of this HoTe3 compound at significantly lower temperatures up to 2.8 K for two perpendicular directions in magnetic fields up to 7 T. It turns out that at T=2.8 K the MC is positive and linear for resistance component along the c direction and sublinear and approximately two times smaller for the a direction. The MR anisotropy observed indicates a strongly anisotropic reconstruction of the Fermi surface due to CDW and may provide useful information about it. Earlier, linear MR was observed in such materials with CDW as quasi-lD NbSe3 [3], quasi-2D transition metal trihalcogenides, TbTe3 and HoTe3 at higher temperatures [2] and was associated with the dependence of the electron scattering time at the "hot spots" of the Fermi surface zhs on the magnetic field, zhs œ 1/Н [2]. The deviation from the linear MR for only one direction indicates a strong anisotropy of the Fermi surface in the CDW state and the competition of several electron scattering mechanisms, including "hot spots", crystal defects, etc.
Financial support from RScF (project #22-42-09018) is acknowledged.
Literature
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2. Sinchenko, A. A., Grigoriev, P. D., Lejay, P., & Monceau, P. Linear magnetoresistance in the charge density wave state of quasi-two-dimensional rare-earth tritellurides / /Physical Review B. - 2017. -T. 96. - № 24. - C. 245129.
3. Richard J., Monceau P., Renard M. Nonlinear magnetoresistance and charge-density-wave depinning at liquid-helium temperatures in NbSe3 // Physical Review B. - 1987. - T. 35. - № 9. C. - 4533.
