We utilize an inverted heterostructure grown on (311)A GaAs to realize
a two-dimensional hole gas (2DHG) with a built-in back gate. The dens
ity of the 2DHG is easily and reproducibly varied between 5 x 10(9) an
d 5 x 10(11) cm(-2). The mobility of the 2DHG is highly anisotropic in
the (311)A plane. (C) 1997 American Institute of Physics.