Implementing arbitrary multi-mode continuous-variable quantum gates with fixed non-Gaussian states and adaptive linear optics

TL;DR

This paper introduces a measurement-based approach to implement complex multi-mode non-Gaussian quantum gates using fixed ancillary states and adaptive linear optics, enhancing resource efficiency and experimental feasibility for optical quantum computing.

Contribution

It presents a novel method for directly implementing multi-mode, higher-order non-Gaussian gates with fixed ancillary states, improving upon existing techniques.

Findings

Enables efficient implementation of multi-mode non-Gaussian gates

Facilitates realization of important gates like the two-mode cubic QND and three-mode Toffoli

Accelerates progress toward fault-tolerant universal quantum computing with light

Abstract

Non-Gaussian quantum gates are essential components for optical quantum information processing. However, the efficient implementation of practically important multi-mode higher-order non-Gaussian gates has not been comprehensively studied. We propose a measurement-based method to directly implement general, multi-mode, and higher-order non-Gaussian gates using only fixed non-Gaussian ancillary states and adaptive linear optics. Compared to existing methods, our method allows for a more resource-efficient and experimentally feasible implementation of multi-mode gates that are important for various applications in optical quantum technology, such as the two-mode cubic quantum non-demolition gate or the three-mode continuous-variable Toffoli gate, and their higher-order extensions. Our results will expedite the progress toward fault-tolerant universal quantum computing with light.