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O: Fachverband Oberflächenphysik

O 4: Transport: Quantum Dots, Quantum Wires, Point Contacts I (TT jointly with O)

O 4.13: Vortrag

Montag, 31. März 2014, 12:45–13:00, BEY 81

Overhauser effect in spin blockaded double quantum dots-the case of dual hysteresis — •Bhaskaran Muralidharan and Siddharth Buddhiraju — Electrical Engineering Department, Indian Institute of Technology Bombay, Mumbai, India

In the spin blockade transport regime through GaAs double quantum dots (DQD), experiments [1] revealed that the hyperfine interaction with host nuclei can have profound consequences on the electron-spin dynamics. One of which, is the observation of bistablity and flat-topped behavior in the current versus applied DC magnetic-field characteristics. In this talk, we will first explain the essence of this flat-topped hysteretic behavior using a simple six-state model that captures the multiple-feedback mechanisms that are involved. We will then consider a more detailed model that elucidates the role of the physical parameter space of the DQD set up and a feedback mechanism involving the difference Overhauser field caused by the two separate nuclear spin baths of the DQD set up.
K. Ono and S. Tarucha, Phys Rev Lett., 92, 256803 (2004).