Observation of quantum interference as a function of Berry's phase in a complex Hadamard optical network

TL;DR

This paper demonstrates quantum interference modulated by Berry's phase in a complex optical network, highlighting potential for error-resistant quantum computation using geometric phase gates.

Contribution

It presents an experimental realization of geometric phase embedding in a loop-free optical network, enabling phase-controlled quantum interference.

Findings

Quantum interference varies with Berry's phase

Geometric phase can be embedded without closed loops

Potential for error-resistant quantum computation

Abstract

Emerging models of quantum computation driven by multi-photon quantum interference, while not universal, may offer an exponential advantage over classical computers for certain problems. Implementing these circuits via geometric phase gates could mitigate requirements for error correction to achieve fault tolerance while retaining their relative physical simplicity. We report an experiment in which a geometric phase is embedded in an optical network with no closed-loops, enabling quantum interference between two photons as a function of the phase.