Efficient Linear Optics Quantum Computation

TL;DR

This paper demonstrates that linear optical elements combined with photo-detectors and feedback can implement reliable quantum algorithms, making linear optics a promising platform for quantum computation.

Contribution

It shows that passive and active linear optics with photo-detectors can perform reliable quantum computation, highlighting the role of feedback and minimal overheads.

Findings

Single photon sources can be built with active linear optics and photo-detectors.

Feedback from detectors enables reliable quantum algorithms.

Linear optics-based quantum computation has low overheads.

Abstract

We investigate the computational power of passive and active linear optical elements and photo-detectors. We show that single photon sources, passive linear optics and photo-detectors are sufficient for implementing reliable quantum algorithms. Feedback from the detectors to the optical elements is required for this implementation. Without feedback, non-deterministic quantum computation is possible. A single photon source sufficient for quantum computation can be built with an active linear optical element (squeezer) and a photo-detector. The overheads associated with using only linear optics appear to be sufficiently low to make quantum computation based on our proposal a viable alternative.