Resonant Microwave Mediated Interactions Between Distant Electron Spins

The ability to transfer quantum states and generate entanglement over distances much larger than qubit length scales is an important step towards maximal parallelism and the implementation of two-qubit gates on arbitrary pairs of qubits. Extending qubit interactions beyond the nearest neighbor is particularly beneficial for spin-based quantum computing architectures, which are limited by short-range exchange interactions. Experimental progress towards achieving long-range spin-spin coupling has so far been restricted to interactions between individual spins and microwave photons [1,2,3]. We demonstrate resonant microwave-mediated coupling between two electron spins that are physically separated by more than 4 mm [4]. Our results imply that microwave-frequency photons may be used as a resource to generate long-range two-qubit gates between spatially separated spins.

[1] Mi et al., Nature 555, 599 (2018)
[2] Samkharadze et al., Science 359, 1123 (2018)
[3] Landig et al., Nature 560, 179 (2018)
[4] Borjans et al., arXiv:1905.00776 (2019)