A quantum sensor beats the standard limit using qubit geometry

Nishchay Suri of Lawrence Berkeley National Laboratory and colleagues have developed a quantum sensing protocol that moves beyond the standard quantum limit by exploiting a geometrical phase within coupled qubit-oscillator systems. The protocol encodes signals in this geometrical phase, which is proportional to the area enclosed by oscillator motion in phase space, and amplifies that area through squeezing. This method is notable for its independence from the oscillator’s initial state and its compatibility with high-temperature or error-corrected qubits, qualities the researchers say emphasise its practicality for The work demonstrates applications in force sensing and high-precision measurements within circuit quantum electrodynamics architectures. A new quantum sensing protocol uses the area enclosed by an oscillator’s motion in phase space to achieve sensitivities exceeding the standard quantum limit (SQL), a benchmark in precision measurement. Researchers Ames Research Center demonstrated that encoding the signal in a…