Quasi-isotropic orbital magnetoresistance in lightly doped SrTiO3

Clément Collignon (1, 2) , Yudai Awashima (3) , Ravi Ravi (2) , Xiao Lin (2) , Carl Willem Rischau (2) , Anissa Acheche (1) , Baptiste Vignolle (4, 5) , Cyril Proust (4) , Yuki Fuseya (3, 6) , Kamran Behnia (2) , Benoît Fauqué (1)

1 JEIPCdF - Jeunes Équipes de l'Institut de Physique du Collège de France
2 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
3 Department of Engineering Science
4 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
5 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
6 Institute for Advanced Science

A magnetic field parallel to an electrical current does not produce a Lorentz force on the charge carriers. Therefore, orbital longitudinal magnetoresistance is unexpected. Here we report on the observation of a large and nonsaturating magnetoresistance in lightly doped SrTiO3−x independent of the relative orientation of current and magnetic field. We show that this quasi-isotropic magnetoresistance can be explained if the carrier mobility along all orientations smoothly decreases with magnetic field. This anomalous regime is restricted to low concentrations when the dipolar correlation length is shorter than the distance between carriers. We identify cyclotron motion of electrons in a potential landscape tailored by polar domains as the cradle of quasi-isotropic orbital magnetoresistance. The result emerges as a challenge to theory and may be a generic feature of lightly doped quantum paralectric materials.

Domaines: Matériaux

Clément Collignon, Yudai Awashima, Ravi Ravi, Xiao Lin, Carl Willem Rischau, et al.. Quasi-isotropic orbital magnetoresistance in lightly doped SrTiO3. Physical Review Materials, 2021, 5 (6), 065002 (6 p.). ⟨10.1103/PhysRevMaterials.5.065002⟩. ⟨hal-03268463⟩