Quantum interference in Wilkinson power dividers

Scaling up quantum technologies entails the challenge of developing large-scale and high-performance photonic quantum networks. Engineering novel optical components, with a compact footprint and advanced functionalities, might help addressing this challenge by reducing the size and complexity of optical networks. Here, quantum interference phenomena in Wilkinson power dividers (WPDs), a popular element of microwave networks, is investigated. It is theoretically demonstrated that WPDs grant access to coherent perfect absorption (CPA) quantum state transformations (single photon CPA, coherent absorption of N00N states, two-photon nonlinear absorption, and absorption of coherence in squeezed light) in CPA networks with a smaller footprint and a reduced number of elements. Additionally, it is shown how a WPD can be designed in a pure silicon-on-insulator platform by taking advantage of radiative losses. These findings might represent an important step forward in the development of CPA quantum networks.