An ultrafast laser emits vastly multimode light over a broad spectral band, a.k.a. the optical frequency comb (OFC), but the emission happens but one photon at a time, if in a stimulated manner, and no entanglement is created in the light. Changing the gain medium from linear (one photon) to nonlinear (two photon) yields an optical parametric oscillator which features massively multipartite entanglement of the OFC modes, as demonstrated experimentally by our group and others. This entanglement can then be exquisitely tailored to cluster states with specific graphs, in particular the two-dimensional ones that are universal for measurement-based, one-way quantum computing. This requires only sparse experimental resources that are highly compatible with integrated optics, thereby paving the way to the realization of practical quantum computers.
About the Speaker:
Olivier Pfister is a professor of physics the University of Virginia, a fellow of the American Physical Society, and a member of the Optical Society of America. His general research area is atomic, molecular, and optical physics, with past interests in ultrahigh resolution laser spectroscopy, symmetry effects in small molecules, nonlinear optics for optical frequency chains, and two-photon lasers. His current research interests are quantum computing with light and quantum measurements at the ultimate precision.