Error-corrected quantum sensing

Quantum sensors exploit the strong sensitivity of quantum systems to external disturbances to measure various signals in their environment with high precision. However, the same strong coupling to the environment also limits their sensitivity due to its decohering effects. 

Error correction strategies, including quantum error correction codes and dynamical decoupling, can help in fighting decoherence, but they incur the risk of also canceling the coupling to the signal to be measured. Here I will show various strategies, focusing in particular on quantum error correction codes, that exploit ancillary qubits to achieve an advantageous compromise between noise and signal cancellation, thus improving the sensitivity of the quantum sensor.