Executive Summary : | Topological condensed matter Systems (TCMS) have become a popular research choice for material scientists due to their robustness in nonlocal orders. These systems are expressed in terms of Berry curvatures, which need to be estimated to obtain the Chern numbers, or topological invariants. The two popular variants of TCMS are Weyl semimetals (WSM) and nodal line semimetals (NLSM). WSMs show massless Weyl fermions in momentum space, topologically robust Weyl charges, and surface Fermi arcs, while NLSMs feature topological nodal rings in the bulk Brillouin zone.
The proposed project aims to rigorously study these semimetals, their topological and quantum oscillation signatures, and their exoticness towards quantum transport and Andreev transport in the presence of time-dependent magnetic and/or electric fields. Magnetotransport is special in WSMs due to negative magnetoresistance and planar Hall conductivity. The project will explore various possibilities in this direction, such as the effect of periodic driving, Floquet analysis, nonequilibrium transport phenomena, and the effect of different tilting on conductivities. Extensive study will be conducted on how different variants of dispersions, effective masses, and strong electromagnetic fields can lead a NLSM to different topological regimes. Emphasis will be given to time periodic field variations, which can result in inter-level charge transfer and interesting modifications to conductivity. The project also plans to study Andreev transport via NS, SNS, or NSN superconducting junctions formed on topological semimetals, especially in the presence of a strong but less than critical field. |