Magnetic field sensing beyond the standard quantum limit using 10-spin NOON states.
Quantum entangled states can be very delicate and easily perturbed by their external environment. This sensitivity can be harnessed in measurement technology to create a quantum sensor with a capability of outperforming conventional devices at a fundamental level. We compared the magnetic field sensitivity of a classical (unentangled) system with that of a 10-qubit entangled state, realized by nuclei in a highly symmetric molecule. We observed a 9.4-fold quantum enhancement in the sensitivity to an applied field for the entangled system and show that this spin-based approach can scale favorably as compared with approaches in which qubit loss is prevalent. This result demonstrates a method for practical quantum field sensing technology.
Jones
Jonathan A
JA
Centre for Advanced Electron Spin Resonance (CAESR), Clarendon Laboratory, Oxford University, Oxford OX1 3PU, UK.
Karlen
Steven D
SD
Fitzsimons
Joseph
J
Ardavan
Arzhang
A
Benjamin
Simon C
SC
Briggs
G Andrew D
GA
Morton
John J L
JJ