Lateral carrier tunnelling in stacked In(Ga)As/GaAs quantum rings W. Ouerghui, J. Martinez-Pastor, J. Gomis, M. A. Maaref, D. Granados and J. M. García Eur. Phys. J. B, 54 2 (2006) 217-223 Published online: 22 December 2006 DOI: 10.1140/epjb/e2006-00444-x