Anupam Mazumdar

Canadian Institute for Theoretical Astrophysics (CITA), University of Toronto, ON M5S 3H8, Ontario, Canada
University of Groningen,  Van Swinderen Institute, 9747 AG,  Groningen,  The Netherlands
Emails:  anupam.mazumdar@utoronto.ca,    anupam.mazumdar@rug.nl

I have written about 240 scientific papers, including three significant reviews published in Physics Reports (2003, 2011), Annual Reviews (2010), and Reports on Progress in Physics (2019) on topics related to particle physics and cosmology. A white paper dedicated to the experimental protocol to test the quantum nature of gravity in a lab (2025). 

In addition, I have researched many different areas of theoretical physics, including classical and quantum gravity, quantum information theory, particle physics, and cosmology. I believe that the most impactful paper of my career is to conceive a protocol to test the quantum nature of gravity in a tabletop experiment, despite the weakness of gravity," Spin Entanglement Witness for Quantum Gravity", Phys.Rev. Lett. 119 (2017) 24, 240401. Building on that, in 2022 I proposed testing the quantum analogue of a light-bending experiment in a quantum optics setup, "Gravitational Optomechanics: Photon-Matter Entanglement via Graviton Exchange" 2209.09273 [gr-qc]. These two experimental protocols will inevitably help us to understand the deeper aspects of spacetime and the foundations of quantum mechanics and quantum gravity via quantum information theory.

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The illustration below depicts the quantum superpositions of two nanodiamonds with embedded  NV-centres when brought sufficiently close to each other, which can entangle via virtual massless spin-2 graviton exchange, and also via virtual photon exchange in quantum electrodynamics (also via two-photon virtual exchanges for higher multipoles). Electromagnetic interactions can be shielded, but gravity can't, leading to a hide-and-seek game (to mitigate the electromagnetic background) to unravel the nature of the graviton in the QGEM experiment proposed in the above papers. These nanodiamonds will be levitated on a current-carrying chip, cooled (internally and motionally) close to the quantum ground state, spun to achieve gyroscopically stable motion (like a rifling bullet), and then created in a spatial superposition via the Stern-Gerlach scheme to perform one-loop interferometry within 0.1 -1 second (requires extreme quantum manipulations of enhancing the quantum coherence of the NV spin). At 1-10 Hz, this will be the most sensitive quantum sensor we can build on Earth for detecting acceleration, gravity gradients, and electromagnetic noise. This discovery machine can also unravel the secrets of axions, neutrinos, and the fifth force, and deepen our understanding of what we mean by the quantum superposition of spacetime.