Variational optical phase learning on a continuous-variable quantum compiler

TL;DR

This paper demonstrates an experimental continuous-variable quantum compiler using two mode-squeezed light to learn Gaussian unitaries, achieving higher precision and faster solutions by tuning the cost landscape with variable squeezing.

Contribution

It introduces a CV quantum compiler that leverages tunable squeezing to improve learning precision and efficiency in quantum process learning.

Findings

Achieved a 5.4-fold increase in phase estimation precision.

Realized a 3.6-fold reduction in time-to-solution.

Demonstrated effective learning of Gaussian unitaries with CV quantum resources.

Abstract

Quantum process learning is a fundamental primitive that draws inspiration from machine learning with the goal of better studying the dynamics of quantum systems. One approach to quantum process learning is quantum compilation, whereby an analog quantum operation is digitized by compiling it into a series of basic gates. While there has been significant focus on quantum compiling for discrete-variable systems, the continuous-variable (CV) framework has received comparatively less attention. We present an experimental implementation of a CV quantum compiler that uses two mode-squeezed light to learn a Gaussian unitary operation. We demonstrate the compiler by learning a parameterized linear phase unitary through the use of target and control phase unitaries to demonstrate a factor of 5.4 increase in the precision of the phase estimation and a 3.6-fold acceleration in the time-to-solution metric when leveraging quantum resources. Our results are enabled by the tunable control of our cost landscape via variable squeezing, thus providing a critical framework to simultaneously increase precision and reduce time-to-solution.