Quantum Simulation of Spin-Boson Models with Structured Bath: Toward a Quantum Advantage

The spin-boson model, involving spins interacting with a bath of quantum harmonic oscillators, is a widely used representation of open quantum systems that describe many dissipative processes in physical, chemical and biological systems. Trapped ions present an ideal platform for simulating the quantum dynamics of such models, by accessing both the high-quality internal qubit states and the motional modes of the ions for spins and bosons, respectively. We demonstrate a fully programmable method to simulate dissipative dynamics of spin-boson models using a chain of trapped ions, where the initial temperature and the spectral densities of the boson bath are engineered by controlling the state of the motional modes and their coupling with qubit states [1]. Our method provides a versatile and precise experimental tool for studying open quantum systems. In particular, using the quantum simulator hardware’s noise for simulating dissipative processes is an important ingredient for achieving a quantum advantage, significantly lowering the requirement for hardware noise level than suggested in [2].

[1] K. Sun, M. Kang, H. Huomin et al., Quantum Simulation of Spin-Boson Models with Structured Bath, arXiv:2405.14624

[2] M. Kang et al., Seeking a Quantum Advantage with Trapped-Ion Quantum Simulations of Condensed-Phase Chemical Dynamics, Nat. Rev. Chem. 8, 340-358 (2024)