Simulating spin biology using a digital quantum computer: Prospects on a near-term quantum hardware emulator

TL;DR

This paper demonstrates how digital quantum computers can simulate complex spin dynamics of radical pair reactions, showing promising agreement with classical models and analyzing the impact of noise on simulation fidelity.

Contribution

It introduces a Trotterization-based quantum simulation method for radical pair spin dynamics and assesses its accuracy and noise resilience on near-term quantum hardware.

Findings

Approximately 15 Trotter steps suffice for accurate simulation

Ideal noiseless simulations agree with classical master equations

Realistic noise limits the number of Trotter steps achievable

Abstract

Understanding the intricate quantum spin dynamics of radical pair reactions is crucial for unraveling the underlying nature of chemical processes across diverse scientific domains. In this work, we leverage Trotterization to map coherent radical pair spin dynamics onto a digital gate-based quantum simulation. Our results demonstrated agreement between the idealized noiseless quantum circuit simulation and established master equation approaches for homogeneous radical pair recombination, identifying approximately 15 Trotter steps to be sufficient for faithfully reproducing the coupled spin dynamics of a prototypical system. By utilizing this computational technique to study the dynamics of spin systems of biological relevance, our findings underscore the potential of digital quantum simulation (DQS) of complex radical pair reactions and builds the groundwork towards more utilitarian investigations into their intricate reaction dynamics. We further investigate the effect of realistic error models on our DQS approach, and provide an upper limit for the number of Trotter steps that can currently be applied in the absence of error mitigation techniques before losing simulation accuracy to deleterious noise effects.