Research

My research interest lies in problems pertaining to Condensed Matter Physics. My current research activities include

  • The computational and theoretical investigation of the electronic, optical and thermo-electric properties of different material systems.
  • Theoretical and computational design of semiconductor devices for computing, energy conversion and sensing applications.
  • Nano-electronics, Nano-mechanics & Nano-electro-mechanical Systems.
  • Theoretical and computational study of ion-solid interactions.

Master of Engineering ( Dissertation Work)

Thesis Title - Designing of microwave circuits to probe nano-mechanical resonators.

Advisor - Prof. Ananth Venkatesan, Professor of Physics, Ultra Low Temperature Physics Lab, Indian Institute of Science Education and Research, Mohali.

Duration - Jan 2013 - April 2013 ( 4 months)

Abstract - Nanomechanical resonators are nanoscale analogue of large scale mechanical resonators. The possible applications of these devices range from electrometery, mass sensing, bio­chemical sensing, and oscillators for nano­electronic devices. A nanomechanical resonator is excellent system for studying the motion and quantum nature of near­ macroscopic structures. These devices have feature size from few tens of nanometer to few hundred nanometers and can be modeled by macroscopic parameters such as bulk density and elasticity. They give access to RF and microwave frequencies and have very high mechanical quality factor. These devices are characterised by the miniscule mechanical displacement amplitudes. The detection of the resonator motion requires ultra sensitive motion displacement and detection techniques. Generally these measurements require complex set up. A survey of the several actuation and detection schemes is presented in the work. Most of the electronic displacement detection schemes developed for motion detection involve the designing of microwave circuits. Microwave circuits are used for impedance matching. Microwave resonators are also used for sensing the resonator motion.

The dissertation work involves the designing of matching circuit for NEMS motion. A scheme for impedance matching and resonator design using the quarter wave transformer is also proposed in the work. This work also involves the characterisation of various microwave components and circuits used using Vector Network Analyser and RF Lock­-In-Amplifiers. The quantum mechanical effects can be observed by bringing the mesoscopic devices to its quantum mechanical ground state. This is challenging task and requires sufficiently low temperature. The dilution refrigerators capable of reaching the temperature of few milli Kelvin is required. This work gives exposure to the instruments and apparatus like the dilution refrigerator, vector network analyser and lock­in amplifier required for NEMS measurements.

Thesis Link :-

  1. Singh, A.K., Chandra, D., Kattayat, S. et al. First-Principles Investigation of Electronic Properties of GaAsxSb1 –x Ternary Alloys. Semiconductors 53, 1584–1592 (2019). https://doi.org/10.1134/S1063782619160267