ON THE NATURE OF THE HALL INSULATOR

We have conducted an experimental study of the linear transport proper ties of the magnetic-held induced insulating phase which terminates th e quantum Hall (QH) series in two dimensional electron systems. We fou nd that a direct and simple relation exists between measurements of th e longitudinal resistivity, rho(xx), in this insulating phase and in t he neighboring QH phase. In addition, we find that the Hall resistivit y, rho(xy), can be quantized in the insulating phase. Our results indi cate that a dose relation exists between the conduction mechanism in t he insulator and in the QH liquid. (C) 1997 Elsevier Science Ltd.