Research
Algorithms for many-body quantum physics:
Complex (many-body) quantum system is an umbrella term for models of physical systems that comprise of a large number interacting smaller subsystems, each of which is described by a quantum theory. While the individual subsystems might be easy to analyze, their collective behavior is challenging to capture. My interest here lies in developing classical and quantum algorithms, with rigorous guarantees, for simulating dynamics and equilibrium properties of many-body quantum systems. In particular, I am interested in focussing on many-body open quantum systems, which remain unexplored compared to their closed counterparts. I am also interested in exploring algorithms for dynamics and equilibrium properties of disordered quantum systems (quantum spin-glasses).
Publications
Description and Complexity of non-Markovian open quantum dynamics, arXiv2204.06936.
Transitions in Computational Complexity of Continuous-Time Local Open Quantum Dynamics, PRL (2022).
Convergence Guarantees for Discrete Mode Approximations to Non-Markovian Quantum Baths, PRL (2021).
Theoretical quantum optics:
Theoretical quantum optics has traditionally studied either single systems (such as a single emitter interacting with an optical field) or few-particle phenomena in larger systems (e.g. multi-emitter systems). Recently, we have started studying many-body phenomena in quantum optics, and this has inspired a variety of new (open-system) many-body models. Here, I am particularly interested in studying disordered dissipative models in quantum optics, which closely correspond to a large number of experiments underway in a variety of platforms, and predict new phase transitions in their entanglement properties to inspire and guide current experimental efforts.
Publications
Optimal two-photon excitation of bound states in non-Markovian waveguide QED, PRA (2021).
Few-photon scattering and emission from low-dimensional systems, PRB (2018).
Noisy and uneconded quantum computation:
Current quantum hardware is constrained in terms of the number of qubits. It is therefore not possible to implement fault-tolerant quantum computation and error correction. This opens up the question of what are the limits of unencoded quantum computations, and analogue quantum simulations. Here, my interests lie in providing certifiable bounds, either analytical or classically computable, on the performance of noisy quantum circuits. I am also interested in rigorously identifying the class of problems that can be solved with uneconded noisy quantum computers, and have potential quantum advantage.
Publications
Quantum Advantage and stability to errors in analogue quantum simulators, arXiv:2212.04924.
Classically computing performance bounds on depolarized quantum circuits, arXiv:2306.16360.
Error propagation in NISQ devices for solving classical optimization problems, PRX Quantum (2022).