Research

Quantum critical systems driven out of equilibrium: The diverging length and time scales close to a quantum critical point leads to non-trivial behaviors in many-body systems. Different quantum information theoretic measures, for example entanglement, fidelity, Loschmidt echo, etc. as well as excitation, defect density, are expected to show universal scaling forms in quantum critical systems. We are interested in studying these universal characteristics of systems driven through quantum critical points.

Selected Publications:

• Victor Mukherjee, Uma Divakaran, Amit Dutta and Diptiman Sen; Quenching dynamics of a quantum XY spin- 1 / 2 chain in a transverse field; Phys. Rev. B 76, 174303 (2007).
• Victor Mukherjee, Anatoli Polkovnikov and Amit Dutta, Oscillating fidelity susceptibility near a quantum multicritical point, Phys. Rev. B 83, 075118 (2011).
• Victor Mukherjee, Shraddha Sharma and Amit Dutta; Loschmidt echo with a non equilibrium initial state: early time scaling and enhanced decoherence; Phys. Rev. B 86, 020301(R) (2012).

Quantum Control: Efficient control of quantum systems is an integral part of experiments in different branches of physics, including condensed matter, quantum optics, as well as in the upcoming quantum technologies. We study ways of controlling closed and open quantum systems. For example, we are interested in studying ways of reducing excitations is systems driven across quantum critical points through application of shortcuts to adiabaticity, cooling quantum systems at the quantum speed limit, enhancing efficiency, power or refrigeration in quantum thermal machines, modelling high-precision quantum probes, etc..

Selected Publications

• Victor Mukherjee, Alberto Carlini, Andrea Mari, Tommaso Caneva, Simone Montangero, Tommaso Calarco, Rosario Fazio, and Vittorio Giovannetti, Speeding up and slowing down the relaxation of a qubit by optimal control, Phys. Rev. A 88, 062326 (2013).
• Victor Mukherjee, Analia Zwick, Arnab Ghosh, Xi Chen and Gershon Kurizki; Enhanced precision bound of low-temperature quantum thermometry via dynamical control, Communications Physics 2, 162 (2019).
• Andreas Hartmann, Victor Mukherjee, Wolfgang Niedenzu and Wolfgang Lechner, Many-body quantum heat engines with shortcuts to adiabaticity, Phys. Rev. Research 2, 023145 (2020).

Quantum Thermodynamics and Quantum Technologies: Systems at the microscopic scale and at low temperatures, abide by the laws of quantum mechanics. On the other hand, they are also expected to follow the laws of thermodynamics. How do we combine the two? We study the thermodynamics of systems in the quantum regime. For example, how do the quantum properties of systems, such as quantum coherence, entanglement, etc. affect the thermodynamics of these systems? We are also interested in modelling technologies based on quantum systems, such as quantum thermal machines, quantum probes, etc., and studying control protocols to realize quantum technologies exhibiting quantum advantage, i.e., quantum technologies which can outperform equivalent classical technologies.

Selected Publications

• Wolfgang Niedenzu, Victor Mukherjee, Arnab Ghosh, Abraham G. Kofman and Gershon Kurizki, Quantum engine efficiency bound beyond the second law of thermodynamics, Nature Communications 9, 165 (2018).
• Victor Mukherjee, Abraham G. Kofman and Gershon Kurizki, Anti-Zeno quantum advantage in non-Markovian heat machines, Communications Physics 3, 8 (2020).
• A. Das and V. Mukherjee, A quantum enhanced finite-time Otto cycle, Phys. Rev. Research 2, 033083 (2020).