Bias-free access to orbital angular momentum in two-dimensional quantum materials

DOI: 10.1103/PhysRevLett.132.196401

Authors: Jonas Erhardt (Universität Würzburg) , Cedric Schmitt (Universität Würzburg) , Philipp Eck (Universität Würzburg) , Matthias Schmitt (Universität Würzburg; Diamond Light Source) , Philipp Kessler (Universität Würzburg) , Kyungchan Lee (Universität Würzburg) , Timur Kim (Diamond Light Source) , Cephise Cacho (Diamond Light Source) , Iulia Cojocariu (Elettra-Sincrotrone; Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH; Università degli Studi di Trieste) , Daniel Baranowski (Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH) , Vitaliy Feyer (Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH; Universität Duisburg-Essen) , Louis Veyrat (Universität Würzburg; IFW Dresden; CNRS-INSA-UJF-UPS) , Giorgio Sangiovanni (Universität Würzburg) , Ralph Claessen (Universität Würzburg) , Simon Moser (Universität Würzburg)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Letters , VOL 132

State: Published (Approved)
Published: May 2024
Diamond Proposal Number(s): 30583

Abstract: The demonstration of a topological band inversion constitutes the most elementary proof of a quantum spin Hall insulator (QSHI). On a fundamental level, such an inverted band gap is intrinsically related to the bulk Berry curvature, a gauge-invariant fingerprint of the wave function’s quantum geometric properties in Hilbert space. Intimately tied to orbital angular momentum (OAM), the Berry curvature can be, in principle, extracted from circular dichroism in angle-resolved photoemission spectroscopy (CD-ARPES), were it not for interfering final state photoelectron emission channels that obscure the initial state OAM signature. Here, we outline a full-experimental strategy to avoid such interference artifacts and isolate the clean OAM from the CD-ARPES response. Bench-marking this strategy for the recently discovered atomic monolayer system indenene, we demonstrate its distinct QSHI character and establish CD-ARPES as a scalable bulk probe to experimentally classify the topology of two-dimensional quantum materials with time reversal symmetry.

Journal Keywords: Quantum spin Hall effect; Monolayer films; Angle-resolved photoemission spectroscopy; Topology

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Other Facilities: NanoESCA at Elettra

Added On: 09/05/2024 08:55

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)