Universal Behavior of Magnetoresistance in Organic Dirac Electron Systems

Ryotaro Kobara; Shin Igarashi; Yoshitaka Kawasugi; Ryusei Doi; Toshio Naito; Masafumi Tamura; Reizo Kato; Yutaka Nishio; Koji Kajita; Naoya Tajima

doi:10.7566/JPSJ.89.113703

paper

Universal Behavior of Magnetoresistance in Organic Dirac Electron Systems

arXiv:2010.09160 · doi:10.7566/JPSJ.89.113703

Abstract

In-plane magnetoresistance for organic massless Dirac electron system (OMDES) $α$ -(BEDT-TTF) $_{2}$ I $_{3}$ and $θ$ -(BEDT-TTF) $_{2}$ I $_{3}$ in addition to possible candidates of the OMDES $α$ -(BETS) $_{2}$ I $_{3}$ and $α$ -(BEDT-STF) $_{2}$ I $_{3}$ , was investigated under hydrostatic pressure. We have found the universal behavior of the in-plane magnetoresistance under a low magnetic field perpendicular to two-dimensional plane. As for $α$ -(BEDT-TTF) $_{2}$ I $_{3}$ , the universality was examined with the parameters of temperature, magnetic field and its direction. We suggest that the universal magnetoresistance behavior is found even for the gapped state of $α$ -(BEDT-TTF) $_{2}$ I $_{3}$ under intermediate pressure, when the thermal energy exceeds the gap.

11 pages, 4 figures