Source of entangled coherent states
Differing from today’s single photon sources, which have emerged primarily from quantum optics applications, our novel chip-based SURQUID ECS source will provide non-classical states which can be employed outside a laboratory setting. The integrated ECS source will provide key technological advances beyond the quantum sensing application, e.g. For continuous variable quantum computation, gravitational interferometry, and quantum enhanced precision measurements. We will realize an optical parametric amplifier (OPA) pumped from a frequency-doubled pulsed C-band laser. The corresponding wavelengths (~1550 nm) are an optimal compromise between ranging resolution, high atmospheric transmittance, and interfacing with nanophotonic circuits and waveguide-coupled superconducting nanowire single-photon detectors (SNSPDs). Depending on the channel loss the source will be tuned via the pump parameter settings and fast switching to yield coherent states (CS), N00N-states, non-Gaussian entangled (or MM’) states or entangled coherent states (ECS).Within the project all these states will be experimentally verified (e.g. via violation of Bell inequalities or similar entanglement criteria). The source will be implemented in a portable form factor (prototype) for deployment in the field.