Correlation-driven organic 3D topological insulator with relativistic fermions

Abstract

Exploring new topological phenomena and functionalities induced by strong electron correlation has been a central issue in modern condensed-matter physics. One example is a topological insulator (TI) state and its functionality driven by the Coulomb repulsion rather than a spin-orbit coupling. Here, we report a "correlation-driven" TI state realized in an organic zero-gap system $\alpha$-(BETS)${}_2$I${}_3$. The surface metallic state that emerges at low temperatures exhibits characteristic transport properties of a gapless Dirac semimetal, evidencing the presence of a topological surface state in this compound. Moreover, we observe a topological phase switching between the TI state and non-equilibrium Dirac semimetal state by a dc current, which is a unique functionality of a correlation-driven TI state. Our findings demonstrate that correlation-driven TIs are promising candidates not only for practical electronic devices but also as a field for discovering new topological phenomena and phases.

36 pages including 10 figures

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Cited by in corpus (5)

• Hybrid-Order Topological Phase And Transition in 1H Transition Metal Compounds
• Three-Dimensional Topological Semimetal/Insulator States in α-Type Organic Conductors with Interlayer Spin-Orbit Interaction
• Wilson Loop and Topological Properties in 3D Woodpile Photonic Crystal
• Wannier Center Analysis on Possible Three-Dimensional Topological Phases in α-Type Layered Organic Conductors
• Ambient-Pressure Organic Dirac Electron State in $\alpha$-(BETS)${}_2$AuCl${}_2$