Two-dimensional electron gas in monolayer InN quantum wells

We report in this letter experimental results that confirm the two-dimensional nature of the electron systems in a superlattice structure of 40 InN quantum wells consisting of one monolayer of InN embedded between 10 nm GaN barriers. The electron density and mobility of the two-dimensional electron system (2DES) in these InN quantum wells are 51015cm2 (or 1.251014cm2 per InN quantum well, assuming all the quantum wells are connected by diffused indium contacts) and 420 cm2/Vs, respectively. Moreover, the diagonal resistance of the 2DES shows virtually no temperature dependence in a wide temperature range, indicating the topological nature of the 2DES.