The simple harmonic oscillator is a ubiquitous model in physics, describing everything from swinging pendulums to vibrating atoms. In the quantum world, these microscopic oscillators are restricted to specific, equally spaced energy levels—effectively forming a "ladder" of energy. An electromagnetic field confined in a cavity behaves exactly like such a harmonic oscillator.

But how do we force this field to climb the ladder and reach a specific, high-energy rung of our choice?

This talk presents a new scheme to achieve large photon states that significantly outperforms current proposals. We show that by combining nonlinearity (where the output is not proportional to the input) with displacement operations (essentially "kicking" the oscillator in phase space), we can guide the system to much higher energy levels than previously possible. We will discuss the mechanism behind this controlled ascent and its potential implications for quantum technologies.

Professor Sivakumar is a theoretical physicist with research interests in Quantum and Classical Dynamics and Statistical Physics. He studied Physics at IIT Madras, Chennai and then joined the Department of Atomic Energy as a scientist. He spent more than two decades researching problems critical to the nation-building objectives of the Department of Atomic Energy. He contributed extensively to the theoretical and experimental physics aspects of the operation and design of the research reactors at the Indira Gandhi Centre for Atomic Research, Kalpakkam. His research interests span from applied research to basic research. His earlier research was on coherent states, atom-field interaction and quantum entanglement. His more recent interests are in the quantum optics-quantum information frontier. He actively pursues issues related to identifying realisable physical systems, the coupled-cavity systems in particular, for use in quantum technology. He is also exploring the manifestations of quantum entanglement in condensed matter systems.

He is passionate about teaching physics at all levels and has two decades of experience teaching various courses for undergraduates, post-graduates, and research scholars. Before joining Krea University, he was with the Homi Bhabha National Institute and the Chennai Mathematical Institute. He has mentored many physics and engineering students, many of whom have taken up research careers.