CPM Seminar

Ultrafast Quantum Photonics: Beating Decoherence with Fast Light

Ben Sussman

National Research Council & University of Ottawa

Short optical pulses, with durations typically ranging from femtoseconds to picoseconds, are of increasing interest for quantum processing. Brief time-bins for encoding information presents an interesting approach, especially in scenarios where decoherence occurs swiftly. The encoding allows numerous operations to be conducted before the system experiences significant decoherence, preserving the integrity of the quantum state.

In this context, we discuss the development of two key components that are essential for optical quantum technologies: a switch (using the Kerr effect in single mode fibres) and a photon memory (using a fibre cavity). The switch is designed to control the path of single photons, without adding noise. The quantum memory for single photons also addresses a key scaling challenge: the temporary storage of quantum states without loss of coherence. Such a memory enables the synchronization of quantum processes by holding quantum states until they are needed for further operations.

We then discuss the use of these components for photonic quantum processing and quantum sensing. In photonic quantum processing, we discuss random walks and more general next steps. We also discuss quantum enhanced ranging and approaches to imaging using correlated photons.