Jean-Claude Besse's research
I work on the fabrication of superconducting circuits, and quantum optics in the microwave domain using artificial atoms (see About).
The results of my main projects as a PhD candidate:
Entangled light modes
Quantum optics crucially relies on sources of quantum states of electromagnetic radiation. In this work, we demonstrate a source of entangled modes of microwave radiation that is fully deterministic, coherent, versatile, and scalable. Full quantum state tomography is performed up to 4 modes, and process maps of the sequential emission process allow us to find entanglement lengths of order ten photonic qubits.
Parity is an important statistic of physical systems. Here, we go beyond single photon detection and measure the parity of radiation reflected from a detector in single shot. We showcase the parity measurement on Fock states, demonstrate direct Wigner tomography of itinerant quantum light fields, and generate Schrödinger cat states.
Single photon detection
Information is often transmitted using electromagnetic radiation, the quantum units of which are photons. In the microwave regime, detecting single itinerant photons at the receiving end of a transmission channel is challenging since microwave photons possess 5 orders of magnitude less energy than their optical counterparts. In this work, we show how to transfer the information content of a propagating photon into an excitation of a stationary qubit. By reading out the state of the latter, we acquire knowledge about the photon’s presence without destroying it. This ‘non-demolition’ aspect opens up new possibilities of detecting the photon in flight while allowing it to travel on towards another destination.
Other projects I've been involved in:
My work, mostly in the clean room, also supported: