Nanometer Scale Quantum Thermometer

• US 20160018269A1
• Filed: 04/01/2014
• Published: 01/21/2016
• Est. Priority Date: 04/02/2013
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: MAURER, Peter Christian, NOH, Hyun Ji, KUCSKO, Georg, LUKIN, Mikhail D., PARK, Hongkun, KUBO, Minako
• Granted Patent: US 10,436,650 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01K 11/20 using thermoluminescent materials G01K11/32 takes precedence
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 2211/00 Thermometers based on nanotechnology
• CPC Class Codes: G01K 7/32 using change of resonant frequency of a crystal

Abstract

An approach to nanoscale thermometry that utilizes coherent manipulation of the electronic spin associated with nitrogen-vacancy (NV) color centers in diamond is disclosed. The methods and apparatus allow for detection of temperature variations down to milli-Kelvin resolution, at nanometer length scales. This biologically compatible approach to thermometry offers superior temperature sensitivity and reproducibility with a reduced measurement time. The disclosed apparatus can be used to study heat-generating intracellular processes.

Claims

1. A method of measuring temperature comprising:

providing an electron spin system comprising a diamond NV center proximal to a heat source, said diamond NV center having a temperature-dependent zero-field splitting of its ground electronic spin state;

applying an optical pulse to polarize the ground electronic spin state;

applying a plurality of microwave pulses to alter the spin population of the spin system;

applying a series of optical pulses to the spin system and measuring a spin-state-dependent fluorescence rate to detect the spin projection of the electronic ground state of the NV center.

2. The method of claim 1, wherein the temperature can be detected at the micro to nanometer scale.

3. The method of claim 1, further comprising analyzing the collected fluorescence to determine the temperature dependent zero-field splitting.

4. The method of claim 1, wherein the plurality of microwave pulses comprises a 2π

-echo-pulse sequence or its equivalent variations.

5. The method of claim 1 wherein the microwave pulse is detuned from the zero-field splitting by 0 MHz to 500 MHz of the resonant frequency.

6. The method of claim 1, wherein the evolution time is in the range of 0 μ

s to 10000 μ

s.

7. The method of claim 1, wherein the temperature sensitivity ranges from 10 K/Hz^1/2 to 50 μ

K/Hz^1/2.

8. The method of claim 1, wherein the heat source has a temperature between 100K and 600K.

9. The method of claim 1, wherein the amount of ¹³C impurity in the diamond is 0.0001% to 1.2%.

10. A method of measuring temperature comprising:

providing electron spin systems comprising a plurality of diamond NV centers proximal to a heat source, each diamond NV center having a temperature-dependent zero-field splitting of its ground electronic spin state;

simultaneously applying a continuous microwave pulse and a continuous optical pulse to the spin system to induce a temperature dependent evolution of the electronic spin state; and

measuring a spin-state-dependent fluorescence rate to detect the spin projection of the electronic ground state of the NV center.

11. The method of claim 10, further comprising analyzing the collected fluorescence to determine the temperature dependent zero-field splitting.

12. The method of claim 10, wherein the microwave energy is detuned from the zero field splitting of the ground state.

13. The method of claim 10, wherein the microwave energy is detuned by 10 Hz to 500 MHz of the resonant frequency

14. The method of claim 10, wherein the temperature sensitivity is in the range from 10 K/Hz^1/2 to 50 μ

K/Hz^1/2.

15. The method of claim 10, wherein the plurality of diamond NV centers comprises 100-10000 NV centers.

16. The method of claim 10, wherein the plurality of diamond NV centers is located within a nanodiamond sensor of 10-5000 nm in size, determining the spatial resolution of the measurement.

18. The method of claim 10, wherein the plurality of diamond NV centers maybe located within a living organism.

17. (canceled)

19. (canceled)

20. An apparatus for measuring temperature comprising:

an electron spin system comprising at least one diamond NV center having a temperature-dependent zero-field splitting of the electronic spin state;

a first optical source of photons configured to polarize the electronic spin into one spin projection;

a microwave source to induce microwave manipulation of the electronic spin state;

a second optical source of photons configured to optically induce fluorescence; and

a detector configured to measure the spin projection via produced fluorescence to determine the zero-field splitting.

21. The apparatus of claim 20, wherein the first and second optical sources comprise a single laser.

22. The apparatus of claim 20, wherein a microwave synthesizer is coupled to an antenna or microwave strip line to drive the electronic spin transition frequency with a microwave field.

23. (canceled)

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

28. (canceled)