We are happy to announce that our work has been published in AVS Quantum Science. In this special edition publication, we commemorate not only the important research of the late Jonathan P. Dowling, but also his notoriously wacky sense of humour. We demonstrate two-photon entanglement in the transverse spatial mode degree of freedom, particularly where one photon carries the fundamental Gaussian mode and the other a higher order Laguerre-Gaussian mode with index (ℓ) or radial (p). Taking inspiration from Dowling’s N00N states, we call these ℓ00ℓ-entangled states (we leave it up to your imagination as to what the radial (p) states may be called) .
Using the combination of a spatial light modulator (SLM) and a single mode fibre (SMF), we can make arbitrary coherent projective measurements on our generated ℓ00ℓ states. This allows us to demonstrate a “twisted” quantum eraser where Hong-Ou-Mandel interference is recovered between two distinguishable photons by projecting them into a rotated LG superposition basis. Furthermore, we verify entanglement by using an entanglement witness and reconstructing the density matrix. We find that our generated ℓ00ℓ states have fidelities of 95.31% and 89.80% to their respective ideal maximally entangled states.
You can read the (open-access) publication here: https://pubs.aip.org/avs/aqs/article/5/4/045004/2920276/00-entanglement-and-the-twisted-quantum-eraser
BBQ Lab 