Quantum simulation of Singlet Fission in a trapped ion platform

Trapped ions provide a pristine platform for quantum simulation of spin and spin–boson models, enabling high-fidelity unitary control and dissipative dynamics relevant to chemical and biological systems ^[1]. Singlet fission is a multi-excitonic process that converts one photoexcited singlet excitation on a molecular or ionic site into two triplet excitations ^[2]. In principle, singlet fission could enable surpassing conventional photovoltaic efficiency limits, but predictive design rules are still elusive because the conversion yield depends on a delicate balance of coherence, vibronic resonance, exchange, and environmental relaxation ^[3].

   Here, we model singlet fission in an ion crystal by engineering an effective spin-1 Hamiltonian using the ground-state hyperfine and Zeeman sublevels of the  manifold to encode the singlet ground, singlet excited, and triplet states. We analyze the motional-mode couplings required to generate effective singlet fission interaction and to transport excitation across lattice sites. We present an experimental configuration that enables both on-site interactions and inter-site couplings, allowing singlet fission and delocalization of singlet and triplet excitations across the ion crystal.

[1] V. So et al., Sci. Adv.10, eads8011(2024)

[2] Smith. M. B., Michl. J., Annu.Rev.Phys.Chem.64.361–386 (2013)

[3] Campaioli. F, et al., PRXEnergy.3.043003 (2024)