Faculty Directory

Design new materials in form of thin films, interface or super-lattice for magneto-opto-electronic devices and understanding their physical properties.

A. Designing New materials in thin film or interface form using laser molecular beam epitaxy.

B. 2-Dimensional electron gas at oxide interface.

C. Strong spin orbit couple system: Rashba effect.

D. Magnetic Skyrmions.

E. Strain induced artificial physical properties.

F Super-lattice for integrated or emergent physical properties.

G. Double perovskite oxides for half metallic antiferromagnets.

DST acknowledged the work by  Dr. Suvankar Chakraverty and his group in an article titled by Mobile 2D electron gas at oxide interfaces by INST is a promising candidate in modern electronic devices. The research by Dr. Suvankar Chakraverty and his group from INST has been carried out through world-class capabilities to produce highest-quality oxide thin films, interface and heterostructures and novel measurements of emergent phenomena arising from quantum phenomenon coupled with the theory of relativity:  Rashba Effects (momentum dependent splitting of spin-bands in an electronic system) in 2d-electron gas at the interface of two insulating oxide layers, where the magnetic state of an electron (q-bit) can be control using electric field. It exhibits a perfect blending of the theory of relativity and quantum mechanical phenomena.The study has important consequences for not just basic physics but also applications to spintronics, memory devices, dissipationless electronics and quantum devices.
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Neha Wadehra et. al. paper got published in Nature Communication titled "Planar Hall effect and anisotropic magnetoresistance in polar-polar interface of LaVO_3-KTaO_3 with strong spin-orbit coupling" in Feb. , 2020. They reported a novel conducting interface by placing KTO with another insulator, LaVO_3 and reported planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) measurements. This interface exhibits a signature of strong spin orbit coupling. The experimental observations of two fold AMR and PHE at low magnetic fields (B) is similar to those obtained for topological systems and can be intuitively understood using a phenomenological theory for a Rashba spin-split system. 

Click the link for more detail:  https://www.nature.com/articles/s41467-020-14689-z

Neha Wadehra from Dr. Suvankar Chakraverty's group presented the creation of artificial electrical domains on the conducting surface of KTaO3 (KTO) having strong Spin orbit coupling. In this work, a conductive atomic force microscopy tip has been used to induce extremely small electrically active charge domains on the surface of KTO. The versatility of creating such nano domains is that the features can be written and erased with nanometer scale precision. The written signal (phase difference between the written and unwritten regions) on KTO has turned out to be much higher than that on other reported perovskite oxides. Kelvin probe force microscopy measurements are performed to probe the surface potential and work function changes in the regions of nano-electrical domains. Magnetic force microscopy measurements suggest generation of a magnetic field when electrostatic charge is written in a dipolar configuration which can be utilized in future nano-electric devices.
Click the empty space at the right for more details:  https://doi.org/10.1063/1.5087035

Ruchi Tomar et. al. studied the origin of the conductivity at the interface of two insulating perovskite oxides which is a matter of intensive studies.The conductivity generated at the interface of insulating LaVO 3(LVO) and SrTiO3 (STO) is explained in terms of polar catastrophe in the paper "Conducting LaVO_3/SrTiO_3 interface: Is cationic stoichiometry mandatory?"  Here, the authors grown LVO films on (001) TiO 2‐terminated STO substrate employing pulsed laser deposition technique and demonstrate a transition from conducting to insulating interface by changing the La‐ stoichiometry by only 1%, whereby such transition takes place for La‐ deficient films. The effect of cation (non) stoichiometry of LVO film on both carrier density and mobility is studied and compared with previously reported LaAlO 3–STO interface.                                                                                       

Click the empty space at the right for more details: https://doi.org/10.1002/admi.201900941