Measurement-based quantum computing with a spin ensemble coupled to a stripline cavity

TL;DR

This paper demonstrates that a spin ensemble coupled to a stripline cavity can perform full quantum processing through measurement-based entanglement, extending its role from quantum memory to a versatile quantum computing platform.

Contribution

It introduces a method for quantum processing using measurement-based entanglement in a spin ensemble-cavity system, building on existing quantum memory proposals.

Findings

System can perform quantum processing via measurement-based entanglement.

Robustness against dominant error types demonstrated.

Readout technology for non-destructive photon number measurement realized.

Abstract

Recently a new form of quantum memory has been proposed. The storage medium is an ensemble of electron spins, coupled to a stripline cavity and an ancillary readout system. Theoretical studies suggest that the system should be capable of storing numerous qubits within the ensemble, and an experimental proof-of-concept has already been performed. Here we show that this minimal architecture is not limited to storage but is in fact capable of full quantum processing by employing measurement-based entanglement. The technique appears to be remarkably robust against the anticipated dominant error types. The key enabling component, namely a readout technology that non-destructively determines "are there n photons in the cavity?", has already been realised experimentally.