Members of the ZOTERAC consortium have just published an article, whose first author is Dr Bo Meng from ETH Zürich, in which they report the observation of intersubband transitions betrween coupled ZnO/ZnMgO quantum wells. Their findings have been published in Physical Review Applied and the Open Access text can be read here.

Structures of the asymmetric coupled quantum wells investigated in the work. (a) Schematic of the structure. (b) Calculated conduction band structure and wave functions for sample with 1-nm-thick barrier at room temperature (300 K). The main intersubband transitions are labeled with blue arrows.