Berry Curvature of the Dirac Particle in $\alpha$-(BEDT-TTF)${}_2$I${}_3$

Abstract

We examine several properties of the Berry curvature for the organic conductor $\alpha$-(BEDT-TTF)${}_2$I${}_3$ consisting of four bands, which exhibits a zero-gap state with Dirac cones. By adding a small potential acting on two molecular sites, which breaks the inversion symmetry, it is shown that the curvature for the Dirac particles displays a pair of peaks with opposite signs and that each peak increases with decreasing potential. The Berry curvature originating from the property of the wave function is analyzed using a reduced Hamiltonian with a 2x2 matrix based on the Luttinger-Kohn representation, which describes a pair of Dirac particles between the conduction band and the valence band. Two types of velocity fields in the reduced Hamiltonian, whose vector product gives the Berry curvature, rotate around the Dirac point as a vortex. It is also shown that the other bands exhibit another pair of peaks of Dirac particles with a tendency toward merging.

18 pages, 12 figures

References in corpus (4)

• Tilted anisotropic Dirac cones in quinoid-type graphene and alpha-(BEDT-TTF)_2I_3
• Merging of Dirac points in a two-dimensional crystal
• Charge Ordering in alpha-(BEDT-TTF)2I3 by synchrotron x-ray diffraction
• Electronic Properties Close to Dirac Cone in Two-Dimensional Organic Conductor $\alpha$-(BEDT-TTF)${}_2$I${}_3$

Cited by in corpus (12)

• Diffusion of Dirac fermions across a topological merging transition in two dimensions
• Correlation Effects on Charge Order and Zero-Gap State in the Organic Conductor α-(BEDT-TTF)2I3
• Conductivity and Resistivity of Dirac Electrons in Single-Component Molecular Conductor [Pd(dddt)_2]
• Floquet theory of photoinduced topological phase transitions in the organic salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$ irradiated with elliptically polarized light
• Berry Phase of Dirac Nodal Line Semimetal in Single-Component Molecular Conductor
• Predicted Photo-Induced Topological Phases in Organic Salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$
• Nonlinear magnetotransport in a two-dimensional system with merging Dirac points
• Anomalous Spin Transport Properties of Gapped Dirac Electrons with Tilting
• Predicted photoinduced pair annihilation of emergent magnetic charges in the organic salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$ irradiated by linearly polarized light
• Inversion Symmetry and Wave-Function-Nodal-Lines of Dirac Electrons in Organic Conductor alpha-(BEDT-TTF)_2I_3
• Predicted novel type of photoinduced topological phase transition accompanied by collision and collapse of Dirac-cone pair in organic salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$
• Effect of Long-Range Coulomb Interaction on NMR Shift in Massless Dirac Electrons of Organic Conductor