College of Engineering Seminars & Speakers

Back to Listing
IQUIST Seminar Series featuring Dr. Hugo Cable, September 20 at 11am in 190 Engineering Science Building

IQUIST Seminar: "Switch Networks for Photonic Fusion-based Quantum Computing," presented by Hugo Cable, PsiQuantum

Event Type
190 Engineering Sciences Building, 1101 W Springfield Ave, Urbana, IL 61801
Sep 20, 2022   11:00 - 11:50 am  
Hugo Cable, Quantum Architect, PsiQuantum
Hannah Stites
Originating Calendar
IQUIST Seminar Series

Switch Networks for Photonic Fusion-based Quantum Computing


Abstract: Fusion-based quantum computing (FBQC) provides a compelling approach to building a fault-tolerant universal quantum computer, and is well suited to hardware implementation using photonic components — single-photon sources, linear-optical circuits, single-photon detectors, and optical switches.  Sophisticated switch networks are needed in the architecture of the quantum computer to perform operations using feedforward, conditioned on previous photon-detection outcomes.  One important application of switch networks is as key subsystems of hardware used to implement fault-tolerant operations at the level of logical qubits (which are needed in turn for useful quantum algorithms).  Another is multiplexing (“muxing”) stages used with circuits for generating small entangled resource states to boost the probabilities for allocating quantum states.  The performance of these switch networks heavily impacts the machine footprint, due not only to routing efficiency, but also critically to qubit losses and errors.  In this talk, I will present a wide range of new techniques and schemes which enable major improvements in terms of muxing efficiency and reductions in hardware requirements, representing many conceptual developments on switch networks at PsiQuantum over the past few years (arXiv:2109.13760).


Short bio: I have worked at PsiQuantum since 2017 as a Quantum Architect, focusing primarily on the development of optical switch networks.  Prior to this, I was a postdoctoral researcher first at LSU with Prof. Jonathan Dowling, and then at the Centre for Quantum Technologies in Singapore with Assoc. Prof. Kwek Leong Chuan, and the Centre for Quantum Photonics at the University of Bristol in the UK with Prof. Jeremy O’Brien  – working on quantum optics, quantum metrology and sensing, quantum imaging, quantum information and quantum computation.

To watch online go to the IQUIST youtube channel:

For Zoom link you may check the IQUIST calendar weekly email or contact Hannah Stites ( To subscribe to our weekly email for event announcements, please go to

link for robots only