Experimental Confirmation of Massive Dirac Fermions in Weak Charge-Ordering State in α-(BEDT-TTF)_2I_3

Abstract

The electronic structure of weak charge-ordering (CO) state just below the critical pressure in an organic conductor α-(BEDT-TTF)_2I_3 was experimentally investigated using peak structure in the temperature dependence of interlayer magnetoresistance (MR). Based on a minimal model considering multiple Landau levels (LLs), we discuss herein the MR peak as characteristic to multilayer massless/massive Dirac fermion (DF) systems. MR measured in the weak CO state exhibited a clear MR peak, and its magnetic-field dependence was consistent with the LL behavior of a massive DF with a small gap. Results indicate that the weak CO state in α-(BEDT-TTF)_2I_3 is a massive DF state.

17 pages, 4 figures

References in corpus (4)

• Observation of an anisotropic Dirac cone reshaping and ferrimagnetic spin polarization in an organic conductor
• Effects of the Zero-Mode Landau Level on Inter-Layer Magnetoresistance in Multilayer Massless Dirac Fermion Systems
• Chern Insulator Phase in a Lattice of an Organic Dirac Semimetal with Intracellular Potential and Magnetic Modulations
• Quantum Phase Transition in Organic Massless Dirac Fermion System $\alpha$-(BEDT-TTF)${}_2$I${}_3$ under pressure

Cited by in corpus (4)

• Optical properties of massive anisotropic tilted Dirac systems
• Possible Nonlinear Anomalous Thermoelectric Effect in Organic Massive Dirac Fermion System
• Narrow Zero Mode in Organic Massless Dirac Electron System $\alpha$-(BEDT-TTF)${}_2$I${}_3$
• Intervalley Tunneling and Crossover from the Positive to Negative Interlayer Magnetoresistance in Quasi-Two-Dimensional Dirac Fermion System with or without Mass Gap