Deterministic photonic spatial-polarization hyper-controlled-not gate assisted by quantum dot inside one-side optical microcavity

TL;DR

This paper proposes a deterministic hyper-CNOT gate operating on both spatial and polarization degrees of freedom of photons, using quantum dot-cavity systems, enabling scalable quantum computing with current technology.

Contribution

It introduces a novel hyper-CNOT gate that manipulates two degrees of freedom simultaneously, enhancing quantum information processing capabilities.

Findings

Hyper-CNOT gate operates deterministically on two DOFs of photons.

The scheme enables preparation and analysis of four-qubit cluster states.

Implementation is feasible with current quantum dot and cavity technology.

Abstract

Up to now, all the works about constructing quantum logic gates, an essential part in quantum computing, are focused on operating on one degree of freedom (DOF) of quantum systems. Here, we investigate the possibility to achieve a scalable photonic quantum computing based on two DOFs of quantum systems and construct a deterministic hyper-controlled-not (hyper-CNOT) gate operating on both spatial-mode and polarization DOFs of a photon pair simultaneously, by using the giant optical Faraday rotation induced by a single-electron spin in a quantum dot inside a one-side optical microcavity as a result of cavity quantum electrodynamics. With this hyper-CNOT gate and linear optical elements, two-photon four-qubit cluster entangled states can be prepared and analyzed, which gives an application to manipulate more information with less resources. We analyze the experimental feasibility of this hyper-CNOT gate and show that it can be implemented with current technology.