Physics

November 17, 2026 – Physics Colloquium

Michael Foss-Feig

Quantinuum

Digital Quantum Magnetism on a Trapped-Ion Quantum Computer

Abstract: Digital quantum matter—realized when discrete quantum gates approximate continuous time evolution—is susceptible to heating into chaotic, structureless states. Here, we use Quantinuum’s H2 quantum computer to simulate digitized dynamics of the quantum Ising model, suppressing digitization errors well enough to observe thermalization on timescales that severely challenge classical simulation methods. Relaxation of an inhomogeneous state reveals an emergent hydrodynamics due to approximate energy conservation, and we compute the associated diffusion constant. By reprogramming our simulations to take place on a triangular lattice with periodic boundary conditions, we observe thermalization consistent with emergent gauge and topological constraints resulting from lattice frustration. Our results were enabled by continued advances in two-qubit gate quality (native partial entangler fidelities of 99.94(1)%), and establish digital quantum computers as powerful tools for studying (effectively) continuous-time dynamics.

Bio: Michael Foss-Feig is a Theoretical Physics Fellow at Quantinuum, where he works at the frontier of quantum computing and quantum many-body physics. His research has contributed to landmark demonstrations of non-Abelian topological order and digital quantum matter, helping establish quantum computers as powerful tools for scientific discovery. He earned his Ph.D. at the University of Colorado Boulder with Ana Maria Rey at JILA and received the 2013 APS DAMOP Thesis Award for outstanding doctoral research in atomic, molecular, and optical physics. He subsequently held a National Research Council postdoctoral fellowship at NIST. After serving as a staff scientist at the U.S. Army Research Laboratory, he joined Honeywell Quantum Solutions, now Quantinuum, in 2018.

Physics Colloquium

November 17, 2026

Michael Foss-Feig

Quantinuum

Digital Quantum Magnetism on a Trapped-Ion Quantum Computer

Abstract: Digital quantum matter—realized when discrete quantum gates approximate continuous time evolution—is susceptible to heating into chaotic, structureless states. Here, we use Quantinuum’s H2 quantum computer to simulate digitized dynamics of the quantum Ising model, suppressing digitization errors well enough to observe thermalization on timescales that severely challenge classical simulation methods. Relaxation of an inhomogeneous state reveals an emergent hydrodynamics due to approximate energy conservation, and we compute the associated diffusion constant. By reprogramming our simulations to take place on a triangular lattice with periodic boundary conditions, we observe thermalization consistent with emergent gauge and topological constraints resulting from lattice frustration. Our results were enabled by continued advances in two-qubit gate quality (native partial entangler fidelities of 99.94(1)%), and establish digital quantum computers as powerful tools for studying (effectively) continuous-time dynamics.

Bio: Michael Foss-Feig is a Theoretical Physics Fellow at Quantinuum, where he works at the frontier of quantum computing and quantum many-body physics. His research has contributed to landmark demonstrations of non-Abelian topological order and digital quantum matter, helping establish quantum computers as powerful tools for scientific discovery. He earned his Ph.D. at the University of Colorado Boulder with Ana Maria Rey at JILA and received the 2013 APS DAMOP Thesis Award for outstanding doctoral research in atomic, molecular, and optical physics. He subsequently held a National Research Council postdoctoral fellowship at NIST. After serving as a staff scientist at the U.S. Army Research Laboratory, he joined Honeywell Quantum Solutions, now Quantinuum, in 2018.