How plugging into the wall quietly ruins your quantum computer

The 50/60 Hz hum from AC mains power creates magnetic-field fluctuations that subtly shift ion energy levels and corrupt quantum gate operations. By measuring the disturbance pattern relative to the mains cycle and baking corrections directly into control software, the team reduced the dominant detuning error 21-fold with no new hardware. Gate fidelity on a trapped barium ion recovered to 99.93%, and a 16-level qudit algorithm jumped from near-random to 70% success — suggesting that many labs are fighting a fixable, overlooked noise source.