Quantum Computing, Fault Tolerance, Error Correction, Logical Qubits.
underlying physical qubits, if not infinite or indefinite (as long as the machine is powered up.) Coherence extension could be expressed in one of four forms: A factor or ratio relative to the coherence time of a physical qubit. 1.25 for a 25% increase, 2.00 for a doubling or 100% increase, 10 for