Xingrui Song

In a dark laboratory where superconducting chips are cooled to thousandths of a kelvin, a qubit spins under the influence of a magnetic field. A regular qubit rotates in one direction. An antiqubit, its mirror twin, rotates in the opposite direction. Together they form a pair that senses the field twice as sharply as any ordinary pair.

A judge walks into the courtroom but doesn't look at the evidence: he immediately delivers the verdict. That's how the new quantum sensor works: it doesn't measure the signal but directly decides which class it belongs to. In conventional quantum sensing, it's all like a detective story: first you gather clues (measure the signal), then you analyze them.