Abstract: I will discuss our recent quantum simulations of the Schwinger model using IBM's Eagle and Heron processors. The Schwinger model is quantum electrodynamics in 1+1D, and shares features with quantum chromodynamics in 3+1D that describes strong interaction physics. We have prepared the quantum vacuum on lattices using more than 100 qubits, and prepared and time-evolved a hadronic wavepacket for up to 14 Trotter steps, clearly identifying a hadronic light cone. The largest quantum volume we used involved 112 qubits and depth 370, the largest quantum simulation to date. To make this possible, we introduced new algorithms, centered around scalable circuits that take advantage of the discrete translational invariance of the lattice system,  and exponentially converging truncations of long-range interactions. Classical simulations using small and modest lattices were sufficient to exponentially converge parameters of the quantum circuits for simulations on much larger lattices. We performed a suite of simulations utilizing more than one trillion CNOT gates on IBM's Torino quantum computer. These developments take us close to being able to collide hadrons, with the potential of a quantum advantage in the near-term simulations of 1+1D systems. These techniques and results are generally applicable to other confining theories.

References:
1) Scalable Circuits for Preparing Ground States on Digital Quantum Computers: The Schwinger Model Vacuum on 100 Qubits,
Roland C. Farrell, Marc Illa, Anthony N. Ciavarella, Martin J. Savage. e-Print: 2308.04481 [quant-ph]
2) Quantum Simulations of Hadron Dynamics in the Schwinger Model using 112 Qubits
Roland C. Farrell, Marc Illa, Anthony N. Ciavarella, Martin J. Savage. e-Print: 2401.08044 [quant-ph]