# US 9,518,336 B2 · Synthetic diamond materials for quantum and optical applications and methods of making the same

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- Number: US 9,518,336 B2
- Document ID: US9518336B2
- Status: Granted
- Kind: B2
- Application number: 14/646,384
- Filed: 2013-12-04
- Published: 2015-10-22
- Granted: 2016-12-13
- Earliest claimed: 2012-12-13
- Assignees: Element Six Limited; President and Fellows of Harvard College
- Applicants: Element Six Limited; President and Fellows of Harvard College
- Inventors: Matthew Markham; Alastair Stacey; Nathalie De Leon; Yiwen Chu; Brendan John Shields; Birgit Judith Maria Hausmann; Patrick Maletinsky; Ruffin Eley Evans; Amir Yacoby; Hongkun Park; Marko Loncar; Mikhail D. Lukin
- Web page: https://patentgrep.com/patent/US9518336B2

## CPC

- C30B 1/04: Isothermal recrystallisation
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- C30B 29/04: Diamond
- C30B 30/00: Production of single crystals or homogeneous polycrystalline material with defined structure characterised by the action of electric or magnetic fields, wave energy or other specific physical conditions
- C30B 33/02: Heat treatment (C30B33/04, C30B33/06 take precedence)
- G01N 21/64: Fluorescence; Phosphorescence
- C30B 25/02: Epitaxial-layer growth
- G01N 2021/6497: {Miscellaneous applications}
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

A synthetic diamond material comprising one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz. The method for obtain such a material involves a multi-stage annealing process.

## Claims

### Claim 1

A synthetic diamond material comprising one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz,
wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over one or both of: at least 10 seconds; and at least 10 spectral scans,
wherein the synthetic diamond material is chemical vapor deposited (CVD) synthetic diamond material, and
wherein the one or more spin defects are negatively charged nitrogen vacancy (NV−) spin defects, and
wherein the one or more s in defects have a decoherence time T2 at room temperature of at least 500 μs.

### Claim 2 (depends on 1)

A synthetic diamond material according to claim 1, wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is no more than 40 MHz.

### Claim 3 (depends on 1)

A synthetic diamond material according to claim 1, wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over at least 100 seconds.

### Claim 4 (depends on 1)

A synthetic diamond material according to claim 1, wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over at least 100 spectral scans.

### Claim 5 (depends on 1)

A synthetic diamond material according to claim 1, wherein the synthetic diamond material comprises a layer of said spin defects, the layer comprising at least 105 spin defects/cm2 and having a thickness no more than 1 μm.

### Claim 6 (depends on 1)

A synthetic diamond material according to claim 1, wherein at least 50% of the spin defects have a total spectral line width of less than 100 MHz.

### Claim 7 (depends on 1)

A synthetic diamond material according to claim 1, further comprising one or more photonic structures fabricated in the synthetic diamond material.

### Claim 8 (depends on 1)

A diamond-based quantum system comprising:
a synthetic diamond material according to claim 1;
an excitation arrangement configured to optically excite one or more spin defects in the synthetic diamond material; and
a detector arrangement configured to detect photon emission from the one or more spin defects.

### Claim 9

A synthetic diamond material comprising one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz,
wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over one or both of: at least 10 seconds; and at least 10 spectral scans,
wherein the synthetic diamond material is chemical vapor deposited (CVD) synthetic diamond material, and
wherein the one or more spin defects are negatively charged nitrogen vacancy (NV−) spin defects, and
wherein the one or more spin defects are located no more than 1 μm from a surface of the synthetic diamond material.

### Claim 10 (depends on 9)

A synthetic diamond material according to claim 9, wherein said layer comprises 105 spin defects/cm2 to 1011 spin defects/cm2.

### Claim 11

A synthetic diamond material comprising one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz,
wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over one or both of: at least 10 seconds; and at least 10 spectral scans,
wherein the synthetic diamond material is chemical vapor deposited (CVD) synthetic diamond material, and
wherein the one or more spin defects are negatively charged nitrogen vacancy (NV−) spin defects,
wherein the synthetic diamond material comprises a layer of said spin defects, the layer comprising at least 105 spin defects/cm2 and having a thickness no more than 1 μm, and
wherein the thickness of said layer is no more than 100 nm.

### Claim 12

A synthetic diamond material comprising one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz, and
one or more photonic structures fabricated in the synthetic diamond material,
wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over one or both of: at least 10 seconds; and at least 10 spectral scans,
wherein the synthetic diamond material is chemical vapor deposited (CVD) synthetic diamond material, and
wherein the one or more spin defects are negatively charged nitrogen vacancy (NV) spin defects, and
wherein the one or more spin defects are located no more than 1 μm from the one or more photonic structures or within the one or more photonic structures.

### Claim 13

A method of fabricating a synthetic diamond material, the method comprising:
selecting a synthetic diamond material comprising a single substitutional nitrogen concentration of no more than 100 ppb; and
annealing the synthetic diamond material using a multi-stage annealing process comprising:
a first annealing step at a temperature in a range 350 to 450° C. for at least 2 hours;
a second annealing step at a temperature in a range 750 to 900° C. for at least 2 hours; and
a third annealing step at a temperature in a range 1150° C. to 1550° C. for at least 2 hours; said synthetic diamond comprising
one or more spin defects having a full width half maximum intrinsic inhomogeneous zero phonon line width of no more than 100 MHz,
wherein the full width half maximum intrinsic inhomogeneous zero phonon line width is averaged over one or both of: at least 10 seconds; and at least 10 spectral scans,
wherein the synthetic diamond material is chemical vapor deposited (CVD) synthetic diamond material, and
wherein the one or more spin defects are negatively charged nitrogen vacancy (NV−) spin defects.

### Claim 14 (depends on 13)

A method according to claim 13, further comprising implanting a layer of nitrogen into the synthetic diamond material prior to the multi-stage annealing process.

### Claim 15 (depends on 13)

A method according to claim 13, further comprising irradiating the synthetic diamond material prior to the multi-stage annealing process to form vacancy defects.