- Letter
Topological burning glass effect
Phys. Rev. B 106, L140304 – Published 20 October, 2022
DOI: https://doi.org/10.1103/PhysRevB.106.L140304
Abstract
We reveal a topological burning glass effect, where the local response of a system exhibits a topological quantization that is enhanced by an integer due to its environmental coupling. As a paradigmatic platform for this intriguing phenomenon, we study a central spin that is quasiperiodically driven by two incommensurate frequencies, and statically coupled to surrounding spins. In the strong-coupling regime, the adiabatic dynamics of the total system is readily understood to imprint on the central spin an -fold enhanced topological frequency conversion between the two driving frequencies. We argue that the topological burning glass effect is induced by the nonunitary dynamics of the central spin, which locally involves the collective motion of the surrounding spins. Our results are derived in the framework of adiabatic perturbation theory and fully corroborated by exact numerical simulations.