Peter Shor shows quantum information can be protected from errors

Why it matters

Leading physicists doubted that fragile quantum states could ever be protected. Shor's code started the field of quantum error correction, which plans for large, reliable quantum computers rely on.

Related

• Peter Shor shows a quantum computer could factor large numbers quickly (Nov 1994)
• Steane, Calderbank and Shor find a recipe for building quantum codes (1996)
• Threshold theorem shows noisy quantum computers can still compute reliably (Oct 1996)

Sources (4)

• Physical Review A Scheme for reducing decoherence in quantum computer memory
  Primary sourceOct 1, 1995

  “It is shown how to reduce the effects of decoherence for information stored in quantum memory, assuming that the decoherence process acts independently on each of the bits stored in memory.”

• Quanta Magazine How Quantum Computers Will Correct Their Errors
  Independent coverageNov 16, 2021

  “A year later, Shor responded. Classical error-correcting schemes measured individual bits to check for errors, but that approach wouldn’t work for quantum bits, or “qubits,” since any measurement would destroy the quantum state, and hence the calculation. Shor figured out a way to detect whether an error had occurred without measuring the state of the qubit itself. Shor’s code marked the beginning of the field of quantum error correction.”

• arXiv (Peter W. Shor) The Early Days of Quantum Computation
  Independent coverageAug 21, 2022

  “you get the following 9-qubit code that corrects both bit errors and phase errors”

• arXiv (John Preskill) Quantum computing 40 years later
  Independent coverageJun 2021

  “But very good physicists like Rolf Landauer [8], Bill Unruh [9], and Serge Haroche [10] voiced strong skepticism about whether quantum computers could ever work effectively.”