Li: Exploring Correlated Topological Phases in Two-Dimensional TaIrTe4
2025-06-18 11:00 - 12:00 (Europe/Berlin) | IFW, Helmholtzstraße 2001069 Dresden
Speaker: Dr. Jiangxu Li
Institute of Speaker: University of Tennessee, Knoxville / Dept. of Physics and Astronomy
Topics:

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Name: IFW (Zoom: , https://zoom.us/my/meeting.with.jeroen)
Street: Helmholtzstraße 20
City: 01069 Dresden
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Description: TaIrTe4 is an established two-dimensional topological insulator known for exhibiting intriguing quantum states. Around its Fermi level, pronounced Van Hove singularities (VHS) exist in both conduction and valence bands, driving electronic instabilities that prompt charge density wave (CDW) formation [1]. Moreover, the recent observation [2] of a correlated quantum spin Hall effect in this system underscores the necessity to deeply understand electron-electron interactions. In this talk, I will present a combined theoretical and experimental investigation into the correlated electronic phases of TaIrTe4. Using Hartree-Fock Mean Field (HFMF) simulations, we constructed the interacting phase diagram for the CDW configuration. Our calculations systematically explore how varying dielectric constants and interaction strengths influence electronic states. Remarkably, beyond the previously identified dual quantum spin Hall insulator (QSHI) state, our theoretical approach uncovers additional phases, including trivial insulating states, higher-order topological insulators (HOTIs), and metallic phases. Critically, these theoretical insights have been confirmed experimentally through detailed edge-state transport measurements. These measurements clearly validate the presence of the predicted correlated insulator, QSHI, and metallic phases, providing robust experimental backing for our theoretical framework. This work not only enhances our fundamental understanding of topological materials but also paves the way for further exploration of correlated quantum phenomena in two-dimensional systems. Ref: Nano Lett. 17, 467475 (2017); Nature. 628, 515-521 (2024)
