Synthesis and Analysis of Entangled Photonic Qubits in Spatial-Parity Space

TL;DR

This paper introduces a new method for creating and analyzing entangled photonic qubits using the spatial parity of a photon’s transverse distribution, enabling controlled generation of Bell states through classical parameter manipulation.

Contribution

It presents a novel physical realization of photonic qubits based on spatial parity, expanding the tools for quantum information processing.

Findings

Successfully generated Bell states using spatial parity control.

Demonstrated a device projecting parity states onto an even-odd basis.

Showed potential for future quantum information experiments.

Abstract

We present the novel embodiment of a photonic qubit that makes use of one continuous spatial degree of freedom of a single photon and relies on the the parity of the photon's transverse spatial distribution. Using optical spontaneous parametric downconversion to produce photon pairs, we demonstrate the controlled generation of entangled-photon states in this new space. Specifically, two Bell states, and a continuum of their superpositions, are generated by simple manipulation of a classical parameter, the optical-pump spatial parity, and not by manipulation of the entangled photons themselves. An interferometric device, isomorphic in action to a polarizing beam splitter, projects the spatial-parity states onto an even--odd basis. This new physical realization of photonic qubits could be used as a foundation for future experiments in quantum information processing.