Gated wires and interferometers based on Si/SiGe heterostructures

We report the fabrication and study of gated quantum wires and interferometers based on a Si/SiGe heterostructure fabricated by electron lithography and anisotropic ion etching. In the wires, negative magnetoresistance connected with weak localisation effects and in the ring, Aharonov–Bohm oscillations were investigated in the temperature range View the MathML source–View the MathML source. The phase coherence time was found to be due to electron–electron scattering with small energy transfer and magnetic impurity scattering. High magnetic field Aharonov–Bohm oscillations connected with the interference of edge states current have been observed in Si/SiGe ring for the first time.