Entanglement Assisted Non-local Optical Interferometry in a Quantum Network

Optical measurements of weak signals using long-baseline interferometry are fundamentally constrained by optical losses and quantum noise. Distributed quantum entanglement in a quantum network can be used to overcome these limits. In this talk we will present the demonstration of entanglement between quantum memories based on silicon-vacancy (SiV) centers in diamond nanophotonic cavities for non-local phase-sensing measurements. We will show how such non-local phase measurement can be performed using memory-assisted network nodes, photonic mode erasure to remove the which-path information of temporal and spatial optical modes, and nondestructive photon heralding. Finally we will discuss how increasing the optical path to 1.55 km paves the way toward new applications in quantum sensing and metrology.