Single pre-measurement cuts superconducting qubit error rate by about 54% in test
Researchers at the University of Regensburg and international partners report that one extra measurement before a sequence of quantum operations can reduce errors in a superconducting qubit. The qubit's resonance frequency switched unpredictably between two known values because of interactions with material defects. The team prepared the qubit, let it evolve briefly, and measured it to identify the active frequency, then used the result in real time to adjust the control signals. Experiments ran on a superconducting circuit at the Israeli Quantum Computing Center, and the average error rate fell from about 0.14% to 0.065%, a reduction of about 54%, or 77% against the largest error seen without feedback. The results appear in Applied Physics Reviews (2026).