Topological surface currents accessed through reversible hydrogenation of the three-dimensional bulk

Abstract

Hydrogen, the smallest and most abundant element in nature, can be efficiently incorporated within a solid and drastically modify its electronic state - it has been known to induce novel magnetoelectric effects in complex perovskites and modulate insulator-to-metal transition in a correlated Mott oxide. Here we demonstrate that hydrogenation resolves an outstanding challenge in chalcogenide classes of three-dimensional (3D) topological insulators and magnets - the control of intrinsic bulk conduction that denies access to quantum surface transport. With electrons donated by a reversible binding of H+ ions to Te(Se) chalcogens, carrier densities are easily changed by over 10^20 cm^-3, allowing tuning the Fermi level into the bulk bandgap to enter surface/edge current channels. The hydrogen-tuned topological materials are stable at room temperature and tunable disregarding bulk size, opening a breadth of platforms for harnessing emergent topological states.

References in corpus (5)

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• Topological Field Theory of Time-Reversal Invariant Insulators
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Crystal growth and magnetic structure of MnBi2Te4
• Controlling bulk conductivity in topological insulators: Key role of anti-site defects