Experimental realization of a quantum CNOT gate for orbital angular momentum and polarization with linear optical elements

TL;DR

This paper demonstrates an experimental linear optical quantum CNOT gate using polarization and orbital angular momentum of photons, employing a Mach-Zehnder interferometer with polarized beam splitters and a pentaprism.

Contribution

It introduces a novel optical setup for implementing a quantum CNOT gate with stable and simple readout, advancing optical quantum computation.

Findings

Successful experimental realization of a quantum CNOT gate

Stable operation with simple readout process

Potential for integration into optical quantum computing protocols

Abstract

We propose and experimentally demonstrate that a Mach-Zehnder interferometer composed of polarized beam splitters and a pentaprism in the place of one of the mirrors works as a linear optical quantum controlled-NOT (CNOT) gate. To perform the information processing, the polarization and orbital angular momentum (OAM) of the photons act as the control and target qubits, respectively. The readout process is simple, requiring only a linear polarizer and a triangular diffractive aperture before detection. The viability and stability of the experiment makes the present proposal a valuable candidate for future implementations in optical quantum computation protocols.