Dr. Partha Pratim Das - Research Interest

Research Interest

Resistive memory: Currently we are interested in exploring conventional as well as not-so-conventional materials for fabricating and characterizing electrical resistance switching based non-volatile memory device. Conventional materials include single and multilayer binary transition metal oxides. As for the unconventional material, we have so far explored electron rich, highly redox-active polyoxometalate cluster molecule with a view to building high density and multi-level memory. We now plan to further our studies to investigate the role of defects and metal-insulator interface on the resistance switching mechanism. For this work, we occasionally collaborate with Dr. Sib S Mal of Chemistry Department at NIT Karnataka.

This work is supported by SERB-DST (Govt. of India) and VGST (Govt. of Karnataka).

Select publications in this area are:

Supercapacitors and batteries: Supercapacitors are seen as one of the most promising candidates for high-performance, safe, clean, green and economical routes to store and release of non-fossil energy. Designing hybrid materials by integrating double-layer and pseudocapacitive materials is crucial to achieving high-power and high-energy storage devices simultaneously. We are interested in developing hybrid materials (e.g., different types of polyoxometalate molecular clusters anchored onto variety of base materials such as activated carbon, graphene oxide, polypyrrole, etc.) that can be used as electrodes in supercapacitors. For this work, we closely collaborate with Dr. Sib S Mal of Chemistry Department at NIT Karnataka.

This work is supported by NIT Karnataka and CSIR.

Select publications in this area are:

Semiconductor spintronics: This area is a continuation of my previous work done at the University of Cincinnati. At present I am only occasionally active in this topic.

Basic idea here is to explore the use of side-gated semiconductor quantum point contacts (QPCs) for generating strongly spin polarized current by purely electrical means in the absence of any applied magnetic field. Our group at Cincinnati observed an anomalous conductance plateau at conductance value, G = 0.5 × (2e2/h) [P. Debray et al., Nature Nanotechnology 4, 759 (2009)] in an asymmetrically biased InAs quantum point contact with in-plane side gates in the ballistic regime of transport. This is a clear experimental signature of spontaneous spin polarization in the narrow constriction of the InAs based QPC. A non-equilibrium Green’s function (NEGF) approach revealed three ingredients which are necessary to create the spin polarization: an asymmetric lateral confinement, a lateral spin-orbit coupling (LSOC) induced by the lateral confining potential of the QPC, and a strong electron-electron interaction. Although we could demonstrate strong spin polarization in QPC constriction (in presence of LSOC), their integration to build an all-electric spin valve still remains elusive.

I collaborate with Prof. Marc Cahay from University of Cincinnati for this work.

Select publications in this area are:

Proposed research area for next few years:

We are planning to start a new area on development of sensing devices. Central material will be transition metal oxides and their variants embedded in different matrix and then use them to make efficient devices for sensing chemicals and gases.