As a CNRS fellow at Institut Néel, Grenoble during 2012-2015, I worked on the development of scanning Hall probe microscopy (SHPM) for quantitative study of stray magnetic fields produced by high performance micro-magnets in ambient conditions. I have developed a SHPM setup capable of performing high resolution scans (step size 0.1 μm) over large areas (few mm). The setup is being extensively utilized for study of a variety of micro-magnet arrays developed for applications in biology and medicine. Further, I have also gained experience in transport measurements and scanning microSQUID microscopy (SSM) in an inverted dilution refrigerator. I have also worked on the development of micro-magnet arrays using micro-magnetic imprinting (µMI) technique and gained familiarity with characterization techniques such as AFM, SEM etc. (Primary publication: G. Shaw et al, Rev. Sci. Instrum. 87, 113702 (2016)).
I proposed to set up an enhanced SHPM facility at KIIT DU, Bhubaneswar, India.
As a Marie Curie BeIPD-COFUND Postdoctoral fellow at University of Liège during 2015-2017, I have investigated vortex matter in heterostructures of (i) superconductors and thermomagnetically patterned (TMP) micromagnets (Nb/NdFeB) and (ii) superconductors and Permalloy, using quantitative magneto-optical imaging (MOI). (Primary publication: G. Shaw et al, Rev. Sci. Instrum. 89, 023705 (2018), chosen as Editor’s pick and featured on journal cover).
Prior to this, for my Ph.D. at IIT Kanpur (and partly at TIFR), India, I have studied static and driven phases of vortex matter in high quality single crystals of superconductors with weak intrinsic pinning and artificially introduced pinning arrays. I took part in setting up the first-ever MOI facility in India in our group. Detailed investigation of classical and high-Tc superconductors using high sensitivity MOI, transport and bulk magnetization measurements have revealed several interesting phenomena: signatures of a novel interaction-driven freezing transition in the dilute vortex regime in BSCCO, a new non-equilibrium driven jammed vortex state in NbS2, and a metastable vortex state inside a nanopatterned region in a BSCCO single crystal, to name a few.