1. Research themes: Driven systems
Central question: Is it possible to tune the functionality of a material so that it supports non-trivial properties not present in the static system?
Prime examples: 1. Topological phase is engineered out of non-topological phase (
Floquet topological insulator), 2. current is suppressed in the time-evolved state while starting from a current-carrying ground state (
dynamical localization), 3. long-lived thermal state in a driven classical system (
Floquet prethermalization) and many others: see
publications 5, 26, 32, for example.
Open questions for future research: Minimise the heating to achieve the target state, consequences of temporal noise, and many more ...
2. Research themes: Topological phases of matter
Central question: How one can characterise various topological phases in non-interacting systems? are they robust against interaction, disorder? How does drive modify the situation?
Prime examples: 1. Higher-order topological phase is engineered out of lower-order topological phase (
static and Floquet higher-order topological insulator), 2. proximity induced topological superconductivity (
static and Floquet higher-order topological superconductor), 3. real space examination of transport signatures, currents (
topological Anderson insulator), 4. drive-mediated
dynamical synchronization transition in interacting system and many others: see
publications 13, 15, 24, 28, 35 for example.
Open questions for future research: Floquet Anderson insulators and higher-order analogues, translation activity in presence of defects, application to twisted systems and many more ...
3. Research themes: Quantum transport
Central question: How do we come to know about the system of interest from the conductivity tensors? How do transport coefficients change in different regimes such as semi-classical Boltzmann regime, quantum regime and mesoscopic regime?
Prime examples: 1. Electrical Hall and thermal Hall conductivities in Weyl semimetal where Berry curvature plays crucial role (chiral anomaly mediated transport), 2. linear and non-linear conductivity tensors (planar Hall conductivity, circular photogalvanic effect), 3. Landauer Buttiker technique (scattering matrix formalism), Landau levels and Kubo formula (quantum regime) and many others: see publications 16, 23, 27, 36, 41 for example.
Open questions for future research: Current through Josephson junction, Boltzmann transport in superconductor, effect of non-Hermiticity, twisted systems, and many more ...
4. Research themes: Many-body correlated phenomena
Central question: How magnetism and superconductivity emerge in an interacting system? How does the localization property change in an interacting many-body disordered systems?
Prime examples: 1. Hubbard interaction-mediated magnetism in
graphene like systems, 2.
algebraic localization in long-range hopping models (sub-extensive growth of entanglement entropy with
many-body dynamics), 3. interaction-induced
charge order and many others: see
publications 13, 17, 18 and upcoming ones for example.
Open questions for future research: Develop new techniques such as Gutzwiller mean field, renormalization group analysis (analytically) and DMRG (numerically), application to various twisted systems, long-range models, interplay between drive and many more ...
5. Research themes: Quantum information and computation
Central question: How to engineer high-entangled states and characterise them with appropriate measures? How to prepare such states from solid-state systems even in the presence of disorder?
Prime examples: 1.
Majorana zero modes as qubits (topological superconductivity), 2. Floquet anomalous Majorana modes as a possible route to withstand the
disorder to some extent (dynamical robustness of Majorana boundary modes) and many others: see
publications 28, 39 for example.
Open questions for future research: Quantum thermodynamics of open topological systems, quantum engines and batteries from build from topological systems, quantum computations with braiding of Majorana qubits and many more ...
6. Research themes: Quantum phase transition and quantum quench
Central question: How the defects are generated following a quench through a quantum critical point?
How do various quantum information theoretic measures change with quench rate and the critical exponents associated with the quantum phase transition?
Prime examples: 1. Unusual scaling of
decoherence factor for various quench protocols and paths (renormalization of
Kibble-Zurek law), 2.
entanglement between two spins globally connected with the spin chain environment (concurrence in central spin model) and many others: see
publications 1, 2, 9, 10 for example.
Open questions for future research: Quantum correlations, entanglement for various quantum spin, fermionic models in equilibrium and out-of-equilibrium, non-Hermitian counter parts, explorations in spin liquid and spin glass systems, and many more ...
Collaborations:
Collaborators outside India:
2.
Prof. Takashi Oka, University of Tokyo, Tokyo, Japan (formerly at MPIPKS, Germany)
Collaborators inside India:
Apart from the above collaborators, I am also very much grateful to my other academic coworkers, friends such as
Dr. Snehasish Nandy,
Dr. Banasree Sadhukhan,
Dr. Sanjib K. Das, Dr. Xiong Feng,
Arnob K. Ghosh, Debashish Mondal, Sudarshan Saha,
Prof. Uma Divakaran,
Prof. Tutul Biswas
For interested students: Please feel free to drop by D-323 or write to me for a detailed discussion on research topics
