Arnab Banerjee is Assistant Professor of Physics and Astronomy at Purdue University where he joined in 2020 on experimental quantum condensed matter physics. He received his BSc and MSc from the Indian Institute of Technology, Kharagpur, finishing as a silver medalist, and his PhD in Physics at the University of Chicago in 2013 under Thomas Rosenbaum supported by the Chandrasekhar Fellowship. He subsequently held an ORISE Postdoctoral Fellowship and Staff Scientist position at Oak Ridge National Laboratory (2013–2019). He works to build an integrated quantum materials program spanning crystal synthesis, millikelvin thermal transport, neutron scattering, and quantum computation. His research is supported by DOE Basic Energy Sciences, the DOE National Quantum Initiative Quantum Science Center, Army Research Office, National Science Foundation Center for Quantum Technologies, and the W.M. Keck Foundation. He is the recipient of the Research Accomplishment Award and the Director’s Award by UT-Battelle, Postdoctoral Achievement Award by Material Research Society, Ruth and Joel Spira Award for Excellence in Undergraduate Teaching and the IIT Kharagpur Young Alumni Achiever Award.
Presentation Title:
Quantum Computing meets Spectroscopy in Quantum Magnets
Presentation Abstract:
The equivalence between a spin and a qubit is opening a new frontier where quantum processors and real-world experiments directly validate each other, creating a powerful discovery feedback loop in quantum magnetism. In this talk I present results from our recent studies that establish this connection. We demonstrate digital quantum simulation of spin transport in a 1D XXZ magnet via the spin-current autocorrelation function, computing the dynamic response across ballistic, superdiffusive, and diffusive regimes on IBM transmons. By simulating single spin-flip processes and their time evolution on 50 qubits, we access the dynamic spin structure factor S(q,ω), the Fourier transform of the spin-spin correlation function. We present a direct benchmark of quantum simulation against INS measurements of S(q,ω) from KCuF3, establishing a workflow for quantitative validation against experimental neutron data. Cross-validation of S(q,ω) provides a window into real-space, real-time low-energy quantum dynamics and a lower bound to the quantum Fisher information (QFI). We assess agreement through global and local spectral parameters and lay the path ahead for benchmarks on CsCoCl3, 2D neutron data, and thermal transport.