# Cavity-mediated dissipative spin-spin coupling

## TL;DR

This paper investigates how virtual photons in a microwave cavity can mediate dissipative coupling between spins in magnetic materials, revealing controllable mode interactions and the ability to engineer dark and bright collective modes through phase tuning.

## Contribution

It introduces a novel mechanism for cavity-mediated dissipative spin-spin coupling using phase-shifted drives, enabling control over collective mode properties.

## Key findings

- Mode level attraction observed in the spectrum.
- Phase tuning allows switching between dark and bright modes.
- Selective phase application enables engineering of collective modes.

## Abstract

We study dissipative spin-spin coupling in dispersive regime mediated by virtual photons in a microwave cavity. Dissipative coupling between magnetization of each magnetic material and the cavity photons is established by means of two phase shifted driving forces acting on each magnetization. We show that when only one of the magnetization is dissipatively coupled to the cavity, the cavity-mediated spin-spin coupling too, exhibits mode level attraction in the spectrum. By tuning the phase parameter at each ferromagnetic insulator we can shift the order of "dark" and "bright" collective modes with phase difference equal to 0 or \pi. Moreover, by selectively applying the phase shifted field it is possible to construct "dark" and "bright" collective modes with phase difference equal to \pm \pi/2: