Gated superconducting photon detector

Patent metadata

Field	Value
Publication number	US-10386229-B2
Application number	US-201816028293-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	May 16, 2017
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

The various embodiments described herein include methods, devices, and systems for fabricating and operating photodetector circuitry. In one aspect, a photon detector system includes: (1) a first superconducting wire having a first threshold superconducting current; (2) a second superconducting wire having a second threshold superconducting current; (3) a resistor coupled to the first wire and the second wire; (4) current source(s) coupled to the first wire and configured to supply a current that is below the second threshold current; and (3) a second circuit coupled to the second wire. In response to receiving light at the first wire, the first wire transitions from a superconducting state to a non-superconducting state. In response to receiving light at the second wire while the first wire is in the non-superconducting state, the second wire transitions to a non-superconducting state, redirecting the first current to the second circuit.

First claim

What is claimed is:

1. A system, comprising:
a first circuit that includes:
a first superconducting wire having a first threshold superconducting current;
a second superconducting wire having a second threshold superconducting current; and
a resistor connected between the first and second superconducting wires with a first end of the resistor coupled to a first end of the first superconducting wire and a second end of the resistor, opposite to the first end of the resistor, coupled to a first end of the second superconducting wire;

one or more current sources coupled to the first end of the first superconducting wire, the one or more current sources configured to supply a first current that is below the second threshold superconducting current;
wherein the second superconducting wire is electrically coupled to receive current from the one or more current sources through the resistor; and
a second circuit coupled to the first end of the second superconducting wire;
whereby, in response to receiving light of first intensity at the first superconducting wire, the first superconducting wire transitions from a superconducting state to a non-superconducting state, thereby redirecting at least a first portion of the first current through the resistor; and
whereby, in response to receiving light of second intensity at the second superconducting wire while the first superconducting wire is in the non-superconducting state, the second superconducting wire transitions from a superconducting state to a non-superconducting state, thereby redirecting at least a second portion of the first current to the second circuit.

2. The system of claim 1 , wherein the first circuit includes an inductor with a first end of the inductor coupled to a second end of the first superconducting wire and a second end of the inductor, opposite to the first end of the inductor, coupled to a second end of the second superconducting wire.

3. The system of claim 1 , wherein the resistor has a resistance less than a resistance of the first superconducting wire operating in the non-superconducting state.

4. The system of claim 1 , wherein the second circuit has a resistance less than a resistance of the second superconducting wire operating in the non-superconducting state.

5. The system of claim 1 , wherein the first superconducting wire and the second superconducting wire have a same length.

6. The system of claim 1 , wherein the first superconducting wire has a first width and the second superconducting wire has a second width that is less than the first width.

7. The system of claim 1 , wherein the first superconducting wire and the second superconducting wire have a same thickness.

8. The system of claim 1 , wherein the first superconducting wire and the second superconducting wire are each composed of a same superconducting material.

9. The system of claim 1 , wherein the first current is at least 70% of the second threshold superconducting current.

10. The system of claim 1 , wherein the light of first intensity corresponds to a pulse including at least 100 photons.

11. The system of claim 1 , wherein the light of second intensity corresponds to a pulse including only a single photon.

12. The system of claim 1 , further comprising:
a first photon source configured to provide the light of first intensity to the first superconducting wire; and
a second photon source configured to provide the light of second intensity to the second superconducting wire.

13. The system of claim 12 , wherein the first photon source is coupled with the second photon source.

14. The system of claim 1 , wherein a combination of the first current and photoelectrons generated by the first superconducting wire upon receiving the light of first intensity is greater than the first threshold superconducting current.

15. The system of claim 14 , wherein a combination of the first current and one or more photoelectrons generated by the second superconducting wire upon receiving the light of second intensity is greater than the second threshold superconducting current.

16. The system of claim 1 , wherein the light of second intensity is received at the second superconducting wire within 3 ns after receiving the light of first intensity at the first superconducting wire.

17. The system of claim 1 , wherein the second threshold superconducting current is less than the first threshold superconducting current.

18. The system of claim 1 , wherein the second intensity is less than the first intensity.

19. A method for detecting light, comprising:
providing a first current to a first circuit that includes:
a first superconducting wire having a first threshold superconducting current;
a second superconducting wire having a second threshold superconducting current that is less than the first threshold superconducting current; and
a resistor with a first end of the resistor coupled to a first end of the first superconducting wire and a second end of the resistor, opposite to the first end of the resistor, coupled to a first end of the second superconducting wire,
wherein the first current is less than the second threshold superconducting current,
whereby the first current causes the first superconducting wire to operate in a superconducting state;

receiving light of first intensity at the first superconducting wire, whereby the light of first intensity causes the first superconducting wire to transition from the superconducting state to a non-superconducting state and causes redirection of the first current toward the second superconducting wire while the second superconducting wire operates in a superconducting state; and
receiving light of second intensity at the second superconducting wire, whereby the light of second intensity causes the second superconducting wire to transition from the superconducting state to a non-superconducting state and causes redirection of the first current toward a second circuit that is coupled to the first end of the second superconducting wire.

20. The method of claim 19 , further comprising:
measuring a current flowing through the second circuit to determine whether the light of second intensity has been provided to the second superconducting wire.

21. An electronic device, comprising:
a first superconducting wire having a first threshold superconducting current;
a second superconducting wire having a second threshold superconducting current that is less than the first threshold superconducting current;
a resistor coupled in series between the first superconducting wire and the second superconducting wire, with a first end of the resistor coupled to a first end of the first superconducting wire and a second end of the resistor, opposite to the first end of the resistor, coupled to a first end of the second superconducting wire; and
a current source coupled in parallel with the first superconducting wire, and coupled in parallel with a series combination of the resistor and the second superconducting wire.

22. The electronic device of claim 21 , further comprising an inductor, wherein a first end of the inductor is coupled to a second end of the first superconducting wire and a second end of the inductor, opposite to the first end of the inductor, is coupled to a second end of the second superconducting wire.

23. The electronic device of claim 21 , wherein the resistor has a resistance that is less than a resistance of the first superconducting wire while the first superco

Assignees

• Psiquantum Corp

Inventors

• Najafi Faraz
• Ziai Syrus

Classifications

• G01J2001/4446

  Type of detector · CPC title

• G01J2001/442

  Single-photon detection or photon counting · CPC title

• G01J2001/4406

  Plural ranges in circuit, e.g. switchable ranges; Adjusting sensitivity selecting gain values · CPC title

• G01J1/44 Primary

  Electric circuits {(for command of an exposure part G03B7/02)} · CPC title

• G01J1/42 Primary

  using electric radiation detectors (optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10) · CPC title