Landauer-Büttiker approach for nuclear spintronics in the integer quantum Hall regime

Starting from the basic tenets of mesoscopic transport, we develop an extended Landauer-Bttiker approach to understand various experimental features involving the interplay of electronic transport and nuclear spin dynamics observed in the integer quantum Hall regime [1]. The approach developed here entails a phenomenological description of spin resolved inter-edge scattering induced via hyperfine assisted electron-nuclear spin flip-flop processes. A self-consistent simulation framework between the nuclear spin dynamics and edge state electronic transport is presented in order to gain crucial insights into the dynamic nuclear polarization effects on electronic transport and in turn the electron-spin polarization effects on the nuclear spin dynamics. In particular, we show that the hysteresis noted experimentally in the conductance-voltage trace as well as in the resistively detected NMR (RDNMR) lineshape results from a lack of quasi-equilibrium between electronic transport and nuclear polarization evolution. In addition, we present circuit models to emulate such hyperfine mediated transport effects to further facilitate a clear understanding of the electronic transport processes occurring around the quantum point contact. Our models set stage toward theoretical explorations on complex electronic textures in the quantum Hall system that result from spatial complexity of the nuclear spin dynamics.

Reference
[1] 	Aniket Singha, M. H. Fauzi, Y. Hirayama and Bhaskaran Muralidharan, arXiv:1612.02584v1 Phys. Rev. B, (in press) (2017).

BIO OF THE SPEAKER: Dr. Bhaskaran Muralidharan obtained his B.Tech in Engineering Physics from the Indian Institute of technology (IIT) Bombay in 2001, his M. S. and Ph. D in Electrical Engineering from Purdue University, West Lafayette in 2003 and 2008 respectively. Between 2008-2012, he was a post-doctoral associate at the Massachusetts Institute of Technology (MIT) and at the Institute for theoretical Physics at the University of Regensburg, Germany. Since December 2015, he is an Associate Professor at the Department of Electrical Engineering at IIT Bombay, India. He is currently involved in the physics and simulation of non-equilibrium phenomena in a variety of systems including nanodevices, nano and spin thermoelectrics and fundamental limits of modern computation. He was also the recipient of the APS-IUSSTF professorship award in 2014.