Quantum Computing Records & Answers
Reference pages computed from the same primary-source dataset and open model that power the interactive evaluator and the MCP server / API. Every number carries its date and source.
Answers
Common feasibility questions, each answered from the live dataset rather than from a fixed number.
Breaking RSA-2048 needs 1,399 logical qubits and, depending on the error-correction protocol, 1 to 6 million physical qubits. Computed from primary sources.
What is the lowest quantum gate error rate ever demonstrated?The record two-qubit gate error rate is 0.0003 (Trapped-Ion), full per-platform record history with primary sources.
What is the largest quantum computer by qubit count?The largest quantum computer has 1,180 physical qubits (Neutral Atom), per-platform record history with primary sources.
How many physical qubits does one logical qubit need?Error-correction overhead computed from primary sources: ~31.5 physical qubits per logical qubit for the best qLDPC code, 1,011–3,747 for the surface code.
What is a logical qubit?A logical qubit is an error-corrected qubit encoded across many physical qubits: ~31.5 with the best published qLDPC code, more with the surface code. Cost and capacity, from primary sources.
When will quantum computers be able to break RSA-2048?A dated, falsifiable extrapolation from sourced hardware records, not a prediction. Current record qubit counts are about 3.5 orders of magnitude short.
Records by platform
The best demonstrated two-qubit gate error rate and physical qubit count for each hardware type, with the full sourced history behind each figure.
Last record update 2026-03-01. All figures derive from primary, verified papers. Subscribe to receive updates.