[Paper Review] Efficient linear optical quantum computation

Dan E. Browne, Terry Rudolph|arXiv (Cornell University)|May 26, 2004

Quantum Information and Cryptography11 citations

TL;DR

This paper proposes a highly efficient linear optical quantum computation scheme using cluster states generated from maximally entangled photon pairs via linear optics, primarily polarizing beam splitters and photon counters. The method achieves scalable, measurement-based quantum computation with significantly improved resource efficiency over prior approaches.

ABSTRACT

We introduce a new scheme for linear optics quantum computation, with a much greater degree of efficiency and a simpler implementation than previous proposals. We follow the "cluster state" measurement based quantum computational approach, and show how cluster states may be efficiently generated from pairs of maximally polarization entangled photons using linear optical elements, most importantly polarizing beam splitters and photon counters.

Motivation & Objective

• To address the inefficiency of previous linear optical quantum computation schemes that required excessive resources and complex setups.
• To develop a simpler, scalable method for generating cluster states using only linear optical elements and standard photodetectors.
• To enable practical, measurement-based quantum computation by efficiently producing high-fidelity cluster states from entangled photon pairs.
• To reduce the resource overhead in linear optical quantum computing by leveraging polarizing beam splitters and photon counters for state preparation.

Proposed method

• The scheme uses pairs of maximally polarization-entangled photons as resource states for cluster state generation.
• Linear optical elements, especially polarizing beam splitters, are used to manipulate and entangle the photons into a cluster state.
• Photon counters detect specific measurement outcomes, projecting the system into the desired cluster state via post-selection.
• The method relies on measurement-based quantum computation, where quantum gates are implemented through adaptive measurements on the cluster state.
• The architecture avoids the need for nonlinear interactions by using only linear optics and feedforward control.

Experimental results

Research questions

• RQ1 Can cluster states be efficiently generated from entangled photon pairs using only linear optical components?
• RQ2 How can resource efficiency in linear optical quantum computation be significantly improved?
• RQ3 What role do polarizing beam splitters and photon counters play in enabling scalable cluster state preparation?
• RQ4 Can measurement-based quantum computation be realized with minimal nonlinear resources?

Key findings

• The scheme enables efficient generation of cluster states using only linear optical elements and standard photon detectors.
• Polarizing beam splitters and photon counters are sufficient to create high-fidelity cluster states without requiring nonlinear optics.
• The method achieves a substantial reduction in resource overhead compared to previous proposals.
• The approach supports scalable, measurement-based quantum computation with practical implementation in mind.