Welcome to Kukreja Group!
Our group focuses on understanding ultrafast dynamics in electronic and magnetic materials. These materials form an active field of research due to their applications in non-volatile memory, data storage and sensors. We perform in-situ studies of electronic and magnetic materials to monitor the evolution of functional properties following application of voltage, temperature or laser. Specifically, laser excitation provides us with a unique way to manipulate physical properties at femtosecond-picosecond timescales. We are currently working on understanding ultrafast switching in magnetic multilayer systems, metal-insulator phase transitions in ferrites and nickelates, and ultrafast control of polarization in ferroelectric materials.
The main characterization tools utilized in our research group vary from in-lab capabilities such as Magnetic Property Measurement System and Versalab for characterizing electrical and magnetic properties of materials to X-ray studies performed at synchrotrons and x-ray lasers housed in National User Facilities. We utilize advanced characterization techniques such as scanning transmission x-ray microscopy (STXM), time-resolved x-ray diffraction, nano-diffraction and Ptychography, and x-ray photon correlation spectroscopy (XPCS) to investigate materials at nanometer lengthscales and femtosecond-nanosecond timescales. Thin film growth is done using reactive and magnetic sputtering and lithography patterning is used to fabricate nanometer scale structures.
Left to Right: Ultrafast manipulation of magnetite via optical laser, spin injection from cobalt to copper layer in a spintronic device, speckle pattern obtained from orbital ordering in magnetite.