Dr. Nirmal Ganguli

Department of Physics,

Indian Institute of Science Education and Research Bhopal,

Bhauri, Bhopal 462066, India

E-mail: NGanguli[at]iiserb.ac.in

 

 

 

Brief Bio-sketch:

Dr. Ganguli finished his masters and PhD from IIT Bombay, carrying out a significant part of the research work at IACS, Kolkata. He moved to University of Twente, the Netherlands in 2011 and subsequently to Max Planck Institute for Solid State Research, Germany in 2015 for postdoctoral research. He is working as an Assistant Professor at IISER Bhopal since 2016.

 

TWO-DIMENSIONAL ANTIFERROMAGNETIC SPINTRONICS AT PEROVSKITE OXIDE HETEROSTRUCTURE

Antiferromagnetic spintronics is a promising area of research for future technology because of its advantages over conventional ferromagnetic spintronics. Besides being robust against perturbation due to magnetic fields, antiferromagnetic materials produce no stray field and display ultrafast dynamics. In the absence of inversion symmetry in the structure, a strong spin-orbit interaction may lead to Dresselhaus or Rashba effect, facilitating the transfer of angular momentum between the orbital angular momentum of carriers and the spin angular momentum of the localized electrons through spin-orbit torques. Realization of materials exhibiting these properties is thus crucial for technological development along this direction.

 

We have investigated the implications of spin-orbit interaction at charge transfer interfaces of perovskite oxides within the framework of ab initio density functional theory. Our calculations for one unit cell thick SrIrO3 on SrTiO3 substrate reveal an antiferromagnetic insulating ground state with an isolated Ir-5d band lying right above the Fermi level. Combining this nonpolar heterostructure with LaAlO3, a polar perovskite oxide along the 001 direction, we achieve charge transfer at the interface that partially fills the isolated Ir-5d band. This partially filled band exhibits Rashba effect in a two-dimensional antiferromagnetic electron gas confined to the plane of the interface. Our systematic calculations suggest that spin-orbit interaction helps to stabilize antiferromagnetic interaction among the Ir atoms. In view of the previous discussion, the prediction of substantial Rashba effect in a two-dimensional antiferromagnetic electron gas is promising for further developments of antiferromagnetic spintronics technologies.