Official description

This 6-week modular grad course will use a subset of the classic experiments on multi-photon interference as a window into quantum optics, quantum measurement, and quantum information. We will begin with a review of the relevant second-quantized theory for describing few-photon experiments, and discuss the regimes in which quantum & classical optics agree and those where they diverge. In particular, we will learn about photon correlations (the Hanbury-Brown–Twiss effect), what we mean when we say “a single photon has no phase” and “two photons never interfere with each other,” and how to reconcile those statements with the existence of single- and two-photon interferometers. We will study the Hong-Ou-Mandel interferometer and its many cousins and applications, ranging from tests of Bell’s Inequalities and demonstrations of the Quantum Eraser to applications as a Bell-state filter and for quantum teleportation. This will enable a discussion of the role of indistinguishability in quantum interference. We will talk about various sources of single- and two-photon states and nonclassical light more broadly, as well as techniques for characterizing them and their evolution. We will introduce both linear and nonlinear schemes for implementing quantum logic gates for photons. By the end of the course, we aim to touch on the protocols which underlie quantum-computing efforts such as those pursued by Xanadu and PsiQuantum.