Systems and methods for quantum sensing using solid-state spin ensembles

1. A method of quantum sensing, comprising:

obtaining information regarding a target signal in electronic spin states of quantum defects in an ensemble of quantum defects;

mapping the information regarding the target signal from the electronic spin states of the quantum defects to corresponding nuclear spin states associated with the quantum defects;

applying a light pulse to the ensemble of quantum defects to reset the electronic spin states of the quantum defects; and

repeating a readout stage a plurality of times within a readout duration, wherein the readout stage includes:

mapping the information regarding the target signal back from the nuclear spin states to the corresponding electronic spin states; and

applying a data acquisition readout pulse to optically measure the electronic spin states of the quantum defects.

2. The method according to claim 1 , wherein obtaining the information includes:

applying a light pulse to the ensemble of quantum defects to polarize the electronic spin states of the quantum defects; and

performing a sensing sequence to obtain the information regarding the target signal in the electronic spin states of the quantum defects.

3. The method according to claim 2 , wherein the sensing sequence includes one of: an XY decoupling sequence; a correlation spectroscopy sequence; or a DROID-60 decoupling sequence.

4. The method according to claim 1 , wherein mapping the information regarding the target signal from the electronic spin states of the quantum defects to the corresponding nuclear spin states associated with the quantum defects includes applying a microwave (MW) pulse and a radio frequency (RF) pulse to the ensemble of quantum defects.

5. The method according to claim 1 , wherein mapping the information regarding the target signal back from the nuclear spin states to the corresponding electronic spin states includes applying an MW pulse to the ensemble of quantum defects.

6. The method according to claim 5 , wherein the readout stage further includes, after applying the MW pulse, applying a light pulse to the ensemble of quantum defects to repolarize the electronic spin states of the quantum defects.

7. The method according to claim 1 , further comprising determining the information regarding the target signal based upon the optical measuring in the plurality of readout stages.

8. The method according to claim 1 , wherein the ensemble of quantum defects includes an ensemble of nitrogen vacancy (NV) centers in diamond.

9. The method according to claim 1 , wherein the information regarding the target signal includes information regarding a magnetic field signal.

10. The method according to claim 9 , wherein the information regarding the target signal includes information regarding an AC magnetic field signal.

11. The method according to claim 1 , further comprising applying a magnetic bias field to the ensemble of quantum defects during the obtaining, the mapping, the applying, and the repeating.

12. The method according to claim 11 , wherein the magnetic bias field has a magnitude at least three times 51.2 mT.

13. The method according to claim 11 , wherein the magnetic bias field has a range of less than 100 uT.

14. The method according to claim 1 , wherein the number of quantum defects in the ensemble of quantum defects is at least on the order of 10 4 .

15. A quantum sensor, comprising:

an ensemble of quantum defects; and

at least one controller including at least one processor and at least one associated memory storing instructions to be executed by the processor to cause the at least one controller to:

direct application of a sensing sequence of energy pulses to the ensemble of quantum defects to obtain information regarding a target signal in electronic spin states of quantum defects in an ensemble of quantum defects;

direct application of a microwave (MW) pulse and a radio frequency (RF) pulse to the ensemble of quantum defects to map the information regarding the target signal from the electronic spin states of the quantum defects to corresponding nuclear spin states associated with the quantum defects;

direct application of a light pulse to the ensemble of quantum defects to reset the electronic spin states of the quantum defects; and

direct repetition of a readout stage a plurality of times within a readout duration, wherein, in the readout stage, the at least one controller is caused to:

direct application of an MW pulse to the ensemble of quantum defects to map the information regarding the target signal back from the nuclear spin states to the corresponding electronic spin states; and

direct application of a data acquisition readout pulse to the ensemble of quantum defects to optically measure the electronic spin states of the quantum defects.

16. The quantum sensor according to claim 15 , wherein the at least one controller is further caused to direct application of a light pulse to the ensemble of quantum defects to polarize the electronic spin states of the quantum defects prior to the sensing sequence.

17. The quantum sensor according to claim 16 , wherein the at least one controller is further caused to direct application of a light pulse to the ensemble of quantum defects to repolarize the electronic spin states of the quantum defects after the MW pulse in each readout stage.

18. The quantum sensor according to claim 16 , wherein the ensemble of quantum defects includes an ensemble of nitrogen vacancy (NV) centers in diamond.

19. The quantum sensor according to claim 16 , wherein the information regarding the target signal includes information regarding a magnetic field signal.

20. The quantum sensor according to claim 16 , wherein the at least one controller is further caused to direct application of a magnetic bias field to the ensemble of quantum defects at a magnitude at least three times 51.2 mT.