Microsoft (MSFT.O) unveiled the Majorana 2 quantum chip at Build 2026, saying it
now targets a commercially practical quantum computer by 2029. Majorana 2 has 12
qubits, up from 8 in the prior model, and Microsoft says qubit coherence exceeds
20 seconds versus under 12 milliseconds previously. The device uses lead-based
superconducting connectors instead of aluminum. Microsoft says it has halved
its timetable and set 2029 as the current target.