Dresden 2026 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 74: Topological Insulators

TT 74.11: Talk

Thursday, March 12, 2026, 12:15–12:30, CHE/0091

Volkov-Pankratov states in shaped topological insulator nanowires — •Lilian Seyve and Cosimo Gorini — SPEC, CEA, Gif-Sur-Yvette, France

Topological insulators (TIs) host robust electronic states at interfaces where the bulk topological invariant changes, giving rise to protected Dirac surface modes. Beyond these gapless states, Volkov and Pankratov showed that smooth band inversions can also generate massive interface modes, now known as Volkov-Pankratov (VP) states. These states coexist with the topological zero mode and interpolate continuously between topological and bulk physics. While VP states have been studied in planar structures, how they behave in curved systems, such as nanowires, is still very much unknown.

In this work, we explore analytically and numerically how VP states appear in nanowires with cylindrical symmetry, where geometry and confinement strongly influence the electronic structure. Using a Dirac-model description with a smoothly varying mass at the wire's edge, we show how curvature, angular momentum, and longitudinal motion combine to create a set of quantized interface states. We obtain analytical expressions for their energies and spatial profiles and describe how interface curvature affects the physical properties of our system.

Keywords: Nanowire; Topological insulator; Volkov Pankratov; Curved space physics