All-photonic architectures for the generation of Gottesman-Kitaev-Preskill states

Xanadu’s mission is to build quantum computers that are useful and available to people everywhere. Founded in 2009, with headquarters in Toronto, Canada, the company has grown to 250+ employees, many of them scientists, researchers and engineers, working across all disciplines (hardware, software, applications, algorithms) to achieve this goal.
Gottesman-Kitaev-Preskill (GKP) states [1] are a promising candidate for encoding qubits for quantum computation in photonic modes due to their ability to be deterministically entangled into cluster states, the resource states for performing measurement-based quantum computation, by simply interfering them at beamsplitters [2, 3], and due to their inherent error-correction capabilities, notably their ability to correct for photon loss [4], the main source of noise in photonic systems. A promising protocol for generating GKP states from simpler non-Gaussian resource states (squeezed cat states) is known in the literature as the cat breeding protocol [5-7]. In this protocol, squeezed cat states are iteratively combined pairwise at beamsplitters and measured with homodyne detection such that they are distilled into a GKP state. The objective of this project is to generalize the cat breeding protocol for generating GKP states to include arbitrary linear optical transformations, and to include post-selection and feedforward between intermediate rounds of the protocol. The project will combine analytical techniques and numerical simulation/optimization to determine good settings for the interferometer and homodyne settings, as well as co-optimizing the Gaussian boson sampling-based (GBS-based) source of squeezed cat states [8] and the feedforward function between rounds of the protocol to optimize performance and benchmark it against the current state of the art [9].

Faculty Supervisor:

Nicolas Quesada

Student:

Partner:

Xanadu

Discipline:

Physics

Sector:

Information and cultural industries; Manufacturing; Professional, scientific and technical services

University:

Polytechnique Montréal

Program: