Tunable Dirac interface states in topological superlattices
Sprache des Titels:
Englisch
Original Kurzfassung:
Relativistic Dirac fermions are ubiquitous in condensed-matter physics. Their mass is proportional to the
material energy gap and the ability to control and tune the mass has become an essential tool to engineer quantum
phenomena that mimic high-energy particles and provide novel device functionalities. In topological insulator
thin films, new states of matter can be generated by hybridizing the massless Dirac states that occur at material
surfaces. In this paper, we experimentally and theoretically introduce a platform where this hybridization can
be continuously tuned: the Pb1?xSnxSe topological superlattice. In this system, topological Dirac states occur
at the interfaces between a topological crystalline insulator Pb1?xSnxSe and a trivial insulator, realized in the
form of topological quantum wells (TQWs) epitaxially stacked on top of each other. Using magnetooptical
transmission spectroscopy on high-quality molecular-beam epitaxy grown Pb1?xSnxSe superlattices, we show
that the penetration depth of the TQW interface states and therefore their Dirac mass are continuously tunable
with temperature. This presents a pathway to engineer the Dirac mass of topological systems and paves the way
towards the realization of emergent quantum states of matter using Pb1?xSnxSe topological superlattices.
Sprache der Kurzfassung:
Englisch
Journal:
Physical Review B: Condensed Matter and Materials Physics
Forschungs-