OPTICAL ADDRESSING OF INDIVIDUAL TARGETS IN SOLIDS

• US 20150316598A1
• Filed: 12/11/2013
• Published: 11/05/2015
• Est. Priority Date: 12/11/2012
• Status: Active Grant

• Current Assignee: Australian National University, University of Melbourne, NewSouth Innovations Pty Limited (University Of New South Wales)
• Original Assignee: NewSouth Innovations Pty Limited (University Of New South Wales)
• Inventors: ROGGE, Sven, SELLARS, Matthew John, YIN, Chunming, MCCALLUM, Jeffrey Colin, DE BOO, Gabriele Gaetano, RANCIC, Milos, STAVRIAS, Nikolas
• Granted Patent: US 10,416,216 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G01R 29/24 Arrangements for measuring quantities of charge
• CPC Class Codes: G06N 10/00 Quantum computing, i.e. information processing based on quantum-mechanical phenomena

Abstract

This disclosure concerns photonics and in particular the addressing of individual targets in solids. In aspect one there is provided a device comprising a solid substrate with one or more atomic scale targets in the substrate. A laser light is focused on a region of the substrate that contains a single target to selectively cause photoionization of the target. A charge sensor with sub-electron charge sensitivity is focussed on measuring the charge in the region of the substrate that contains a single target. In use, the device operates such that the laser is turned on to cause photoionization of the target, and the charge sensor detects the change in charge in the region of the substrate that contains the single target. In another aspect is the method for optically investigating individual nuclear spin states of single atoms by investigating both the Zeeman effect and the hyperfine interaction of the single atoms.

Claims

1. A device comprising:

a solid substrate;

one or more atomic scale targets in the substrate;

a laser light focussed on a region of the substrate that contains a single target to selectively cause photoionization of the single target;

a charge sensor with sub-electron charge sensitivity focussed on measuring the charge in the region of the substrate that contains a single target;

wherein, in use, the device operates such that the laser light is turned on to cause photoionization of the single target, and the charge sensor detects the change in charge in the region of the substrate that contains the single target.

2. The device according to claim 1, wherein the solid substrate comprises silicon, other III/V and II/VI semiconductors, or dielectric crystals.

3. The device according to claim 1, wherein the targets comprise shallow dopants including Phosphorus (P), Arsenic (As), Antimony (Sb), Bismuth (Bi), Boron (B), Indium (In) and Aluminium (Al), or optically active sites including rare earth ions.

4. The device according to claim 1, wherein the laser light is generated from any laser having suitable wavelength(s).

5. The device according to claim 1, wherein the laser light is delivered to the single target via optical fibres that guide the laser light onto the target, or via laser waveguides into which the device is placed.

6. The device according to claim 1, wherein photoionization occurs via processes, including:

direct photoionization based on a single photon, whether resonant or not;

a two photon process;

a two photon process where at least one of the transitions is resonant;

or,

a resonant excitonic transition that forms a metastable state which decays and leaves the site ionized.

7. The device according to claim 1, wherein the charge sensor comprises the gate of a silicon-on-insulator Single Electron Transistor (SET), or a dielectrics metal SET.

8. The device according to claim 7, utilized to achieve single-shot readout of the optical excitation of a single solid-state centre.

9. The device according to claim 1, wherein the charge sensor device geometry is:

a planar nano transistor,

an accumulation layer Field-Effect Transistor (FET);

a metal Single Electron Transistor (SET) on a dielectric;

a coulomb blockade island charge sensor;

a charge island gate; and

,

a waveguide gate.

10. The device according to claim 1, comprising a Si based Single Electron Transistor (SET) in form of a Fin-Shaped Field Effect Transistor (FinFET) in which optical centres are embedded.

11. The device according to claim 10, wherein the SET is biased such that a small current flows just below, or above, a charge degeneracy point;

the device is illuminated with light from a single mode optical fibre; and

the light is resonant with one of the transitions of the target optical centres it photoionizes, such that it changes the charge state of the atom which is detected by an increase, or decrease, in current in case of a loss of an electron.

12. The device according to claim 11, wherein laser light is used to gain high spectroscopic resolution with access to the electron and nuclear state.

13. A method for optically investigating individual nuclear spin states of single atoms incorporated into a crystalline lattice, comprising the steps of:

performing photoionization spectroscopy at a single-atom;

sensing nano-transistor charge arising from the photoionization spectroscopy at the single-atom;

studying both the Zeeman effect and the hyperfine interaction of the single-atom to determine the state of single atoms and ions incorporated into the crystalline lattice.

14. The method of claim 13, applied to charge-sensing photoionization spectroscopy of dopant atoms incorporated into semiconductors.

15. The method of claim 13, wherein charge detection is based on a Fin-Shaped Field Effect Transistor (FinFET) State Electron Transistor (SET) to observe the resonant photoionization of single Erbium ions in Silicon.

16. The method according to claim 15, wherein resonant photoionization is based on a 15/2 to 13/2 transition observed with sub 1 ueV resolution.

17. The method according to claim 15, wherein Zeeman splitting is observed as well as the hyperfine splitting of the transition.