EXPERIMENTAL-OBSERVATION OF COHERENT BACKSCATTERING IN OPEN BALLISTICMICROSTRUCTURES

We report on observations of coherent backscattering in open devices c onsisting of a quantum point contact and two reflector gates. The devi ces are fabricated in a high-mobility two-dimensional electron gas sys tem, and magnetotransport data are taken at a temperature of 385 mK. U nlike ballistic microstructures in which this effect has previously be en measured, our devices are designed to yield many backscattered traj ectories enclosing very similar areas. An array of these devices has b een measured in order to average away magnetoconductance fluctuations. (C) 1996 Academic Press Limited