Knill, Laflamme and Milburn show how to compute with photons and linear optics

Why it matters

Their protocol made light a serious candidate for building quantum computers and became the starting point for later photonic designs.

Sources (3)

• Nature A scheme for efficient quantum computation with linear optics
  Primary sourceJan 4, 2001

  “Until now, it suffered from the requirement for non-linear couplings between optical modes containing few photons. Here we show that efficient quantum computation is possible using only beam splitters, phase shifters, single photon sources and photo-detectors.”

• arXiv (Knill, Laflamme and Milburn) Efficient Linear Optics Quantum Computation
  Primary sourceJun 20, 2000

  “We show that single photon sources, passive linear optics and photo-detectors are sufficient for implementing reliable quantum algorithms.”

• arXiv (Kok et al.) Review article: Linear optical quantum computing
  Independent coverageDec 9, 2005

  “Linear optics with photon counting is a prominent candidate for practical quantum computing. The protocol by Knill, Laflamme, and Milburn [Nature 409, 46 (2001)] explicitly demonstrates that efficient scalable quantum computing with single photons, linear optical elements, and projective measurements is possible.”