 Quantum error correction

ID: quantum-error-correction

Quantum error correction (QEC) is a crucial aspect of quantum computing that aims to protect quantum information from errors due to decoherence, noise, and operational imperfections. Quantum bits, or qubits, are the fundamental units of quantum information. Unlike classical bits, which can be either 0 or 1, qubits can exist in superpositions of both states. This property makes quantum systems particularly susceptible to errors, as even small interactions with the environment can lead to significant loss of information.

Ciro Santilli 37  Updated 2025-06-12  +Created 1970-01-01

Technique that uses multiple non-ideal qubits (physical qubits) to simulate/produce one perfect qubit (logical).

One is philosophically reminded of classical error correction codes, where we also have multiple input bits per actual information bit.

TODO understand in detail. This appears to be a fundamental technique since all physical systems we can manufacture are imperfect.

Part of the fundamental interest of this technique is due to the quantum threshold theorem.

For example, when PsiQuantum raised 215M in 2020, they announced that they intended to reach 1 million physical qubits, which would achieve between 100 and 300 logical qubits.

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