Aharonov-Bohm-type quantum interference effects in narrow gap semiconductor heterostructures

We present experiments on quantum interference phenomena in semiconductors with strong spin-orbit interaction, using mesoscopic parallel ring arrays fabricated on InSb/InAlSb and InAs/AlGaSb heterostructures. Both external electric field effects and temperature dependence of the ring magnetoresistance are examined. Top-gate voltage-dependent oscillations in ring resistance in the absence of an external magnetic field are suggestive of Aharonov-Casher interference. At low magnetic fields the ring magnetoresistance is dominated by oscillations with h/2e periodicity characteristic of Altshuler-Aronov-Spivak (AAS) oscillations, whereas the h/e periodicity characteristic of Aharonov-Bohm (AB) oscillations persists to high magnetic fields. Fourier spectra (FS) reveal AB amplitudes on the same order as AAS amplitudes at low fields, and in some samples reveal a splitting of the AB peaks, which has been interpreted as a signature of Berry's phase. The FS are also used to quantify the temperature dependence of the oscillation amplitudes (NSF DMR-0618235, DOE DE-FG02-08ER46532, NSF DMR-0520550).