Fig. 1. Research context of quantum multiparameter estimation enhanced by the feedback control

Fig. 2. Scheme of quantum multiparameter estimation enhanced by feedback control

Fig. 3. Experimental scheme of quantum multiparameter estimation based on the linear optical platform^[26]

Fig. 4. Experimental precision of multiple parameters in the quantum control-enhanced sequential scheme^[26]. (a) The parameter α; (b) The parameter θ; (c) The parameter ϕ

Fig. 5. Control-enhanced multiparameter estimation based on the generator vector method^[29]. (a) The enhancement effect of QFI before and after the introduction of quantum control; (b) The relationship among the control-enhanced QFI, the component number N and the vector angle α

Fig. 6. Schematic diagram of the multi-node distributed quantum sensor network^[34]

Fig. 7. The effect of quantum control on the improvement of the parameter estimation precision of rotating magnetic field^[36].

(a) QFI comparison of magnetic field amplitude B before and after introducing quantum control;

(b) QFI comparison of rotating frequency ω before and after introducing quantum control

Fig. 8. (a) Theoretical scheme of control-enhanced quantum multiparameter estimation^[25];(b) Experimental scheme based on the linear optical platform^[25]

Fig. 9. Experimental results of the simultaneous optimal estimation between the amplitudeB and rotating frequency ω of the magnetic field^[25]