In typical topological insulator (TI) systems the TI is bordered by a non-TI insulator, and the
surrounding conventional insulators, including vacuum, are not generally treated as part of
the TI system. Here, we implement a material system where the roles are reversed, and the
topological surface states form around the non-TI (instead of the TI) layers. This is realized
by growing a layer of the tunable non-TI (B i 1− x I nx) 2 S e 3 in between two layers of the TI
B i 2 S e 3 using the atomically precise molecular beam epitaxy technique. On this tunable …

… On this tunable inverse topological platform, we systematically vary the thickness and the
composition of the (Bi1-xInx)2Se3 layer and show that this tunes the coupling between … (MBE)
technique, we report the first implementation of such a system by inserting a layer of a
tunable non- …