Higher-order topological insulator in cubic semiconductor quantum wells

Abstract

The search for exotic new topological states of matter in widely accessible materials, for which the manufacturing process is mastered, is one of the major challenges of the current topological physics. Here we predict higher order topological insulator state in quantum wells based on the most common semiconducting materials. By successively deriving the bulk and boundary Hamiltonians, we theoretically prove the existence of topological corner states due to cubic symmetry in quantum wells with double band inversion. We show that the appearance of corner states does not depend solely on the crystallographic orientation of the meeting edges, but also on the growth orientation of the quantum well. Our theoretical results significantly extend the application potential of topological quantum wells based on IV, II–VI and III–V semiconductors with diamond or zinc-blende structures.

Higher-order topological phases in crystalline and non-crystalline systems: a review

“…In 2 Se 3 ) [341], group-VIB transition metal dichalcogenides (MX 2 material with M = W, Mo and X = Te, Se, S) [327,337] and carbon allotrope with C≡C bond (graphyne and graphdiyne) [58,61,317,320]. Other typical proposals for non-magnetic 2D HOTIs include twisted bilayer graphene and boron nitride for a range of twist angles [57,321], antidot Dirac materials [323], semiconductor quantum wells [325] and so on. There are also many theoretical predictions of magnetic 2D HOTIs, such as bismuth on EuO substrate [318], NpSb [326], CrSiTe 3 [343], 2H-RuCl 2 [335], Janus VSSe [335] and CoBr 2 /Pt 2 HgSe 3 /CoBr 2 van der Waals heterostructure [330].…”

Topological nano-switches in higher-order topological insulators

“…So far only a few materials have been proposed to realise a SOTI in two dimensions (2D). These are twisted bilayer graphene [8], graphdiyne [9], breathing Kagome lattices [10], phosforene [11], and cubic semiconductor quantum wells [12]. Interestingly, SOTIs can be implemented by applying an in-plane Zeeman (or exchange) field to 2D TIs, for example produced by a magnetic substrate, as it was proposed in [13][14][15][16][17][18][19][20].…”

Cap Layer Effect on Key Features of Persistent Photoconductivity Spectra in HgTe/CdHgTe Double Quantum Well Heterostructures

“…They also provide a greater variety of topological phases compared to single HgTe/CdHgTe QWs [18]. In particular, unique topological phases can appear in DQWs, such as the "double inversion" phase, in which the system can be considered as a higher order topological insulator [19]. The latter is currently a hot topic in the physics of topologically non-trivial systems [20][21][22].…”