Working principles of the short-period superlattice structure in GaAs quantum wells*

We present the design rules of GaAs quantum wells that utilize the short-period superlattice (SPSL) structure to achieve a two dimensional electron system (2DES). By changing growth conditions such as doping density, barrier composition, and well width within the SPSL, we show that the density of the 2DES can be tuned from 2.0 x 10¹¹ cm^-2 to 4.5 x 10¹¹ cm^-2 even with a fixed spacer thickness. This implies we can prepare samples that have quite different 2DES density but rather similar scattering conditions. The magnetotransport is analyzed in detail and the influence of the change in 2DES density is discussed, with an emphasis on the strength of the fraction quantum Hall states.