AHARONOV-BOHM EFFECT IN QUASI-ONE-DIMENSIONAL IN0.77GA0.23AS/INP RINGS

Aharonov-Bohm oscillations with a modulation of the resistance amplitude up to 12% have been observed in high mobility In1-xGaxAs/InP rings. The phase coherence length LΦ is extracted from the interference pattern by an analysis of the oscillation amplitude as a function of temperature and electron excess energy. LΦ shows approximately a T-0.5 dependence for temperatures between 2 and 10 K. We attribute this behavior to momentum-nonconserving processes in a quasi-one-dimensional ring structure. Although the widths of the samples are comparable to the Fermi wavelength there is still more than one one-dimensional conducting channel in the ring and the phase coherence length saturates for decreasing temperature. © 1995 The American Physical Society.