Quantum-classical hybrid simulations for nuclear physics

PI: Kazuki Ikeda (The University of Massachusetts Boston)

co-PI: Dmitri Kharzeev and CR Ramakrishnan (Stony Brook University)

Quarks and gluons, governed by Quantum Chromodynamics (QCD), form the fundamental building blocks of hadronic matter such as protons and neutrons.  Alongside QCD, Quantum Electrodynamics (QED) describes the electromagnetic interactions of charged particles like electrons and positrons.  While QED is well-understood perturbatively, QCD remains a deeply non-perturbative theory, especially at low energies and high densities where rich quantum phenomena—such as confinement, mass generation, and chiral symmetry breaking—emerge.  These processes are crucial for understanding the early universe, strongly correlated matter in high-energy regimes, black hole thermodynamics, and the geometric structure of space-time emerging from the entanglement of quantum fields.

Classical computational methods struggle to address such strongly coupled quantum systems, particularly in regimes involving real-time dynamics, finite temperature, and curved space-time.  Quantum computing offers a fundamentally new approach: by leveraging unitary operations, entanglement, and superposition, quantum processors can efficiently simulate the Hilbert space of interacting quantum fields.  However, current devices face significant limitations due to noise, limited coherence time, and restricted circuit depth, which hinder large-scale, fully quantum simulations.  To overcome these challenges, the project employs quantum-classical hybrid algorithms that delegate quantum state preparation and evolution to quantum hardware, while relying on classical resources for optimization, control, and error mitigation—enabling scalable, first-principles studies of gauge theories.

Building on this framework, the proposed research simulates QCD and QED from first principles, incorporating tools from quantum information science (QIS) and exploring deep connections between nuclear/particle physics, condensed matter systems, and space-time geometry.