2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162984We propose and discuss two conjectures on the nature of information leaks (decoherence) for quantum computers. These conjectures, if (or when) they hold, are damaging for quantum error-correction as required by fault-tolerant quantum computation. The first conjecture asserts that information leaks for a pair of substantially entangled qubits are themselves substantially positively correlated. The second conjecture asserts that in a noisy quantum computer with highly entangled qubits there will be a strong effect of error synchronization. We present more general conjectures for arbitrary noisy quantum systems.A revision and an extension of the formal part of quant-ph/0607021. The paper contains new conjectures on general quantum systems and elaborate on the connection with quantum error-correctionQuantum Physicstext