Giant microwave sensitivity of a magnetic array by long-range chiral interaction driven skin effect

Abstract

A non-Hermitian skin effect was observed in one-dimensional systems with short-range chiral interactions. A long-range chiral interaction mediated by traveling waves also favors the accumulation of energy, but has not yet exhibited non-Hermitian topology. Here, we find that the strong interference brought by the wave propagation is detrimental for accumulation. By the suppression of interference via the damping of traveling waves, we predict the non-Hermitian skin effect of magnetic excitation in a periodic array of magnetic nanowires that are coupled chirally via spin waves of a thin magnetic substrate. The local excitation of a wire at one edge by weak microwaves of magnitude $\ensuremath{\sim}\ensuremath{\mu}\mathrm{T}$ leads to a considerable spin-wave amplitude at the other edge, i.e., a remarkable functionality useful for the sensitive, nonlocal, and nonreciprocal detection of microwaves.