Speaker
Description
Gaussian Boson Sampling (GBS) is a leading model of sub-universal quantum computation realizable with current photonic technologies. Despite recent experimental progress, the validation of GBS devices remains an open problem. In this talk, I present results on the asymptotic behavior of photon-number cumulants of multimode Gaussian states and discuss how these quantities can be used as experimentally accessible tools for device validation. After a brief overview of the GBS framework, I introduce a matrix-based approach for computing photon-number cumulants of general Gaussian states, drawing on graph-theoretic structures. By averaging these cumulants over Haar-random interferometers, device-specific details are eliminated, allowing their universal asymptotic scaling with the number of modes to be characterized. I conclude by highlighting the role of Haarpy, a Python library developed to automate the Weingarten calculus underlying these results.