Engineering three-dimensional topological insulators in Rashba-type spin-orbit coupled heterostructures
2013 (English)In: Nature Communications, ISSN 2041-1723, Vol. 4, 1972- p.Article in journal (Refereed) Published
Topological insulators represent a new class of quantum phase defined by invariant symmetries and spin-orbit coupling that guarantees metallic Dirac excitations at its surface. The discoveries of these states have sparked the hope of realizing non-trivial excitations and novel effects such as a magnetoelectric effect and topological Majorana excitations. Here we develop a theoretical formalism to show that a three-dimensional topological insulator can be designed artificially via stacking bilayers of two-dimensional Fermi gases with opposite Rashba-type spin-orbit coupling on adjacent layers, and with interlayer quantum tunneling. We demonstrate that in the stack of bilayers grown along a (001)-direction, a non-trivial topological phase transition occurs above a critical number of Rashba bilayers. In the topological phase, we find the formation of a single spin-polarized Dirac cone at the G-point. This approach offers an accessible way to design artificial topological insulators in a set up that takes full advantage of the atomic layer deposition approach. This design principle is tunable and also allows us to bypass limitations imposed by bulk crystal geometry.
Place, publisher, year, edition, pages
2013. Vol. 4, 1972- p.
IdentifiersURN: urn:nbn:se:su:diva-94057DOI: 10.1038/ncomms2972ISI: 000323624100040OAI: oai:DiVA.org:su-94057DiVA: diva2:651059