Non-Hermitian Spin-Spin Interactions Mediated by Chiral Phonons

Chiral phonons, which are phonons possessing non-zero angular momentum, have garnered significant attention in recent years. These chiral phonons are found in chiral materials and represent the intrinsic asymmetry present in nature. They exhibit a variety of exotic properties, notably their ability to carry magnetic moments, enabling efficient coupling with both electronic and nuclear spins in solid-state systems. In this presentation, we will demonstrate that chiral phonons can mediate non-local, non-Hermitian spin-spin interactions. Specifically, we will show that one spin on the left can influence another spin on the right, but not vice versa. We will argue that under modest experimental conditions, the strength of such non-Hermitian spin-spin interactions can surpass the linewidth of the spins. Moreover, due to their non-local nature, chiral phonons can facilitate interactions among a large ensemble of spins, paving the way for the study of non-Hermitian many-body physics.