Quantum Theory Seminar - Nishad Maskara (Harvard University)

Title: Programmable Quantum Simulation for Molecules and Materials with Reconfigurable Arrays

Abstract: Simulations of  quantum chemistry and quantum materials are believed to be among the most important potential applications of quantum information processors, but realizing practical quantum advantage for such problems is challenging. Here, we introduce a simulation framework for strongly correlated molecules and materials that can be represented by model spin Hamiltonians. Our approach leverages reconfigurable architectures to programmably simulate real-time dynamics and introduces an algorithm for extracting chemically relevant spectral properties via classical co-processing of quantum measurement results. We develop a digital-analog simulation toolbox for efficient simulation utilizing Floquet engineering and hardware-optimized multi-qubit operations to accurately realize complex spin-spin interactions. Furthermore, we present an implementation proposal tailored for Rydberg atom arrays. Then, we show how detailed spectral information can be extracted from dynamics through snapshot measurements and ancilla-assisted control, enabling the evaluation of excitation energies and finite-temperature susceptibilities from a single-dataset.  To illustrate the approach, we show how this method can be used to compute key properties of a polynuclear transition-metal catalyst and 2D magnetic materials.

Faculty Hosts: Eun-Ah Kim, Chao-Ming Jian, and Debanjan Chowdhury