Quantum Expectations: Understanding Quantum Computing Error Rates

This interactive educational tool helps you understand why low error rates and quantum error correction (QEC) are vital for practical quantum computing. JavaScript is required to use the interactive calculator.

Key Concepts

Base Error Rate: The probability of an error occurring during a single quantum operation (typically 10⁻³ to 10⁻² for current hardware).
Effective Error Rate: The cumulative probability that your quantum computation produces an incorrect result.
Quantum Error Correction: Techniques using multiple physical qubits to create more reliable logical qubits. The surface code threshold is approximately 1.4%.

Current Quantum Hardware (2025)

Trapped-Ion: ~98 qubits, 7.92×10⁻⁴ error rate
Superconducting: ~156 qubits, 1.25×10⁻³ error rate
Neutral Atom: ~260 qubits, 8×10⁻³ error rate

Example Requirements

Factoring RSA-2048: ~1,399 logical qubits, 6.5×10⁹ Toffoli gates

Enable JavaScript to use the interactive visualization and calculator.

← Quantum Expectations

Trapped-Ion quantum computing records

As of November 2025, the record two-qubit gate error rate on trapped-ion hardware is 0.0003 (July 2024) and the record physical qubit count is 98 (November 2025). On a log-linear fit of the 3-point record series, the error rate halves every ~5.8 years and the qubit count doubles every ~2.3 years, extrapolations of record data points, not predictions.

Two-qubit gate error rate: record history

Date	Error rate	Source
April 2016	0.00084	arxiv.org/abs/1604.00032
May 2021	0.0006	arxiv.org/abs/2105.05828
July 2024	0.0003	arxiv.org/abs/2407.07694

Physical qubit count: record history

Date	Qubits	Source
March 2016	5	arxiv.org/abs/1603.04512
February 2022	24	www.aqt.eu/about/
May 2023	32	arxiv.org/abs/2305.03766
June 2024	56	arxiv.org/abs/2406.02501
November 2025	98	arxiv.org/abs/2511.05465