High-mobility electron systems in remotely-doped InSb quantum wells

We have achieved high-quality InSb/AlxIn1-xSb quantum-well structures which enable magneto-transport experiments that reveal phenomena unique to InSb. Multiple quantum-well structures exhibit mobilities as high as 380 000 cm( 2) V-1 s(-1) at low temperature and 41 000 cm(2) V-1 s(-1) at room temperat ure. The integer quantum Hall effect is observed in structures containing a single quantum well. No magneto-resistance minima are observed at fraction al Landau-level filling factors but the system remains metallic at filling factors at least as low as 1/2. (C) 1999 Elsevier Science B.V. All rights r eserved.