Dynamical Time-Reversal and Inversion Symmetry Breaking, Dimensional Crossover, and Chiral Anomaly in α-(BEDT-TTF)₂I₃

Abstract

In most Dirac semimetals, time-reversal and inversion symmetries are believed to play a crucial role in their stability. We demonstrate that these symmetries are broken in Dirac fermions in the organic conductor α-(BEDT-TTF)₂I₃ due to the bond correlation created by the strong inter-site electronic correlation. The system is a three-dimensional type-II Dirac semimetal in the coherent inter-layer tunneling regime. A chiral anomaly is predicted to be observed in the magnetoresistance when the magnetic field is tuned to the inter-layer tunneling direction. Our result suggests that α-(BEDT-TTF)₂I₃ is a useful platform to explore interplay between the chiral anomaly and the strong correlation and/or dimensionality.