Condensed Matter Physics Seminar: Dephasing Measurement and Observations of Beating in Aharonov-Bohm Oscillations in InGaAs/AlInAs 2DEG Heterostructures

Abstract:

The InGaAs/AlInAs 2DEG heterostructures were investigated by observing weak anti-localization effect, Aharonov-Bohm oscillations and universal conductance fluctuations to find dephasing properties.

Using magnetoresistance measurements we were able to extract phase coherence length of 2-4 microns at 1.5-4.2 K. We found that the temperature dependence of the dephasing rate complies with the dephasing mechanism originated on electron-electron interactions in all three experiments despite their different dependences on temperature.

We observed beating in the Aharonov-Bohm oscillations for a wide range of magnetic fields of up to 2.6 T in a relatively high temperature of 1.5 K.

The cause of this beating effect could be a result of the interplay between spin orbit interaction and Zeeman splitting as suggested in previous works.

Seminar Organizer: Prof. Sasha Gerber