Research 

My research interest lies in a broad area of theoretical condensed matter physics with expertise in modeling material-specific properties related to topology, quantum geometry, transport, plasmons, and optical response of materials. I use density function theory (DFT) based first-principles techniques along with material-specific tight-binding methods and analytical modeling to discover, understand, and engineer material properties. I am interested in studying a variety of materials, such as two-dimensional materials, heterostructures, and various quantum materials, including magnetic materials, topological materials, Axion insulators, etc. I enjoy working in collaboration with various experimental research groups worldwide. A few highlights from various areas of my research are given below (please refer to the publication list for details).

Quantum Geometry and Transport
Berry curvature and quantum metric are the imaginary and the real part, respectively, of the complex quantum geometric tensor. The quantum metric measures the gauge-invariant “distance” between Bloch wavefunctions at different momenta, while the Berry curvature characterizes the change in the phase of Bloch wavefunction along a closed contour in the Brillouin zone. In the past few decades, the role of Berry curvature has been celebrated widely in various areas of condensed matter physics due to its connection to anomalous Hall conductivity and topological invariants. On the other hand, quantum metric-induced phenomena remained largely unexplored. In close collaboration with experiments, we have made several discoveries on Berry curvature and quantum geometry-related effects. A few selected publications are given below:

Novel Optical Properties of Quantum Materials
I am interested in material-specific modeling of various novel optical properties, including natural optical activity, optical Axion coupling, gyrotropic birefringence, etc. This involves the computation of higher order susceptibility and magneto-electric coupling induced response within the Wannier function formalism by developing home-built codes. Material-specific computation of such optical response is still rare. A few highlights of my work in this area are given below.

Plasmons in Quantum Materials
Plasmons are collective density oscillations that are of enormous importance for designing next-generation optoelectronics devices. The existing open-source codes that are suitable for exploring plasmons using first-principles calculations (for example, GPAW) do not include the effect of spin-orbit coupling, which is a crucial ingredient for studying quantum materials. This has motivated us to develop in-house codes for computing plasmons using Wannier function-based modeling, thus broadening the scope of material-specific study of plasmons. A few highlights of our work in this area include:

Materials Discovery and Characterization
Using high-throughput computational methods, I built an in-house band structure database of ~12500 unique non-magnetic compounds listed in the Pearson Crystal Database. Using this database, we have predicted several new topological materials and stable two-dimensional materials for the first time. Additionally, in close collaboration with angle-resolved photoemission spectroscopy (ARPES) experiments, I have helped characterize a number of new topological materials. A few highlights of our study in this area are given below: 

Engineering Material Properties
Engineering properties of materials to improve their potential for real-world application is highly desired. Two-dimensional materials offer exciting possibilities in this regard. Through heterostructure engineering, chemical doping, and the use of external stimuli like electric field, strain, etc., the electronic properties of a 2D material can be manipulated to a great extent. A few selected studies of our work in this direction are given below. 

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