Title: Simulating the Dicke Model on Qubit-Based and Hybrid Qubit-Boson-Based Quantum Computers
Date and Time: 16th September 2026 & 03:00 PM
Venue: SV Narasaiah Auditorium, IAP Department
Abstract: The Dicke model has long served as a paradigmatic framework for understanding collective quantum phenomena arising from the interaction of many two-level systems with a common bosonic mode. Despite its seemingly simple Hamiltonian, accurately determining its ground- and excited-state properties becomes increasingly challenging as the system size grows, particularly for generalized or inhomogeneous variants.
In our recent work, we ask a simple question: Can near-term quantum computers efficiently simulate such collective many-body systems? Using the Dicke model as a guiding example, I will first introduce the general principles of variational quantum simulation and discuss how physical symmetries can be incorporated directly into quantum-circuit design. We then develop symmetry-preserving variational algorithms that accurately capture both the ground and low-lying excited states of the finite-size Dicke model while keeping the circuits and classical optimization manageable.
Beyond numerical accuracy, this approach reveals broader principles for constructing compact, physically motivated variational ansätze for many-body problems. We demonstrate the feasibility of the qubit-based method through a proof-of-principle implementation on a trapped-ion quantum processor. Finally, I will introduce a complementary hybrid qubit–boson framework that treats bosonic modes as native computational resources, reducing the required qubit overhead and more closely reflecting the structure of the underlying physical model. This approach is particularly relevant to emerging trapped-ion and circuit-QED architectures and offers a promising route toward resource-efficient quantum simulation of more general spin–boson systems.
Bio: Dr. Aravind Plathanam Babu is a DST INSPIRE Faculty in the Department of Instrumentation and Applied Physics at the Indian Institute of Science (IISc). He received his PhD in Engineering Physics from the Quantum Technology Centre of Excellence, Department of Applied Physics, Aalto University, Finland. Prior to joining IISc, he was a Postdoctoral Researcher at the University of Luxembourg (2025) and the University of Oulu, Finland (2022–2024). He has worked extensively on the modelling of open quantum systems, superconducting quantum devices, quantum error correction, and quantum software architectures. His current research focuses on hardware-aware quantum computing and hardware–software co-design, with particular emphasis on crosstalk-aware quantum error correction, hybrid qubit–boson architectures, and variational quantum algorithms for many-body simulation.
Refreshments will be served after the seminar.
