Realization and imaging of superconducting spin-wave optics

Spin waves are collective excitations of the spins in magnetic materials.

They play a central role in the thermodynamics of magnets and are promising signal carriers in classical and quantum information devices.

Spin waves offer non-reciprocal transport, low damping, microscale wavelengths at microwave frequencies, and strong interactions that enable signal conversion.

As such, spin waves have raised the hopes of enabling information technology with functionalities and efficiencies beyond those provided by non-interacting particles. A key requirement is realizing efficient, low-damping spin-wave control. A potentially ground-breaking but virtually unexplored method is provided by superconductors.

Superconductors have no electrical resistance, precluding damping by eddy currents, and a strong diamagnetism that enables stray-field control of the refractive index governing spin-wave transport.

Moreover, superconductors are sensitive to electric currents, magnetic fields, temperature, and light, providing tunability.

As such, superconductors provide unique opportunities for realizing low-damping, tunable spin-wave optical devices.I propose to realize and locally study superconducting spin-wave optics.

I will create spin-wave-optical devices - mirrors, waveguides, beamsplitters, and resonators by harnessing the dissipationless superconducting diamagnetism.

I will then demonstrate the power of superconductor-control by tuning the devices using electric currents, magnetic fields, temperature, and light.

In addition, I propose to use superconductors to engineer spin-wave damping and enter new regimes of flat-band and topological transport.

To locally study spin waves underneath superconductors, I will use magnetic imaging based on spins in diamond a technique pioneered by my lab.

The project thus aims to engineer and understand magnet-superconductor interaction, realize tunable low-damping spin-wave devices, and launch the field of superconducting spin-wave optics.