Phonon-qubit hybrid quantum simulation with trapped ions

Trapped-ion systems are a powerful platform for quantum computing, but scaling to large systems remains a serious challenge. In order to significantly increase the available Hilbert space, we incorporate the quantized vibrational (motional) modes stemming from the ion confinement directly into the computational toolkit. This talk will present results from two distinct experiments demonstrating this capability using a chain of individually addressed Ytterbium ions. First, in a quantum simulation of the phase diagram for Quantum Chromodynamics (QCD), we show how a single quantized motional mode can successfully replace a register of spin ancilla qubits to provide the required dissipation for controlled thermal state creation. In this case, the alternative use of motional ancillae effectively doubles the simulation space supported by the quantum computer. Second, we present an analog-digital hybrid simulation of the Yukawa model, a simplified model of interacting nucleons and pions. High-energy physics models such as this are notoriously challenging due to the complex interactions involved and the infinite-dimensional bosonic Hilbert space, which is costly to map to qubits. The motional modes of trapped ions provide a natural direct representation for these bosons. We results from the first analog-digital hybrid quantum simulation of the Yukawa model that combines both digital gates and qubits with motional modes along multiple directions, demonstrating the substantial resource savings offered by this approach for simulating complex field theories.