IQHE and FQHE in a wire with incompressible and compressible strips

We report the study of the longitudinal (R-L) and Hall (R-H) resistances in a wide ballistic wire (L-H much less than W much less than l, l is mean fr ee path, W is the width of wire, L, is the magnetic length in QHE regime) i n the IQHE and FQHE regimes. It was observed a partial suppression of the R -L minima in the IQHE and their practically total disappearance in the FQHE while the Hall resistance plateaus corresponding to these minima remained well pronounced in both the IQHE and FQHE regimes. At lower filling factors (v < 1/3) we have observed a quantum Hall liquid-quantized Hall insulator transition that takes place at a certain critical magnetic field B, and a c ritical resistance value close to h/e(2). Finally, at v < 1/2 and at the lo west experimental temperatures T < 0.3 K there have been observed correlate d fluctuations in the longitudinal and in the Hall resistance both as a fun ction of magnetic field and gate voltage. It is supposed that the observed features are due to interplay between wide compressible and narrow incompre ssible strips in the wire. (C) 2001 Elsevier Science B.V. All rights reserv ed.