2D lattice of coupled Sinai billiards: Metal or insulator at g << 1?

We investigate the transport in a two-dimensional (2D) lattice of coupled S inai billiards fabricated on the basis of a high-mobility 2D electron gas i n a GaAs/AlGaAs heterojunction in going from g > 1 to g much less than 1 (w here g = sigma/(e(2)/h) is dimensionless conductivity). The data obtained s uggest that the system studied behaves more like a metal than an insulator at g much less than 1 and is not described by the generally accepted pictur e of metal-insulator transition in 2D electron systems. (C) 1998 Published by Elsevier Science B.V. All rights reserved.