# US 10,374,611 B2 · Superconducting logic components

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,374,611 B2
- Document ID: US10374611B2
- Status: Granted
- Kind: B2
- Application number: 16/151,190
- Filed: 2018-10-03
- Published: 2019-04-11
- Granted: 2019-08-06
- Earliest claimed: 2017-10-05
- Assignees: Psiquantum, Corp.
- Applicants: PSIQUANTUM Corp.
- Inventors: Faraz Najafi
- Web page: https://patentgrep.com/patent/US10374611B2

## CPC

- H03K 19/195: using superconductive devices
- H03K 19/1954: {with injection of the control current}
- H03K 19/1958: {Hybrid configuration, i.e. using electromagnetic coupling and injection of the control current}
- H03K 19/20: characterised by logic function, e.g. AND, OR, NOR, NOT circuits (H03K19/003 - H03K19/01 take precedence)
- H03K 19/23: Majority or minority circuits, i.e. giving output having the state of the majority or the minority of the inputs
- H10F 77/959: {for devices working in avalanche mode}
- H10N 60/124: {comprising high-Tc ceramic materials}
- H10N 60/30: Devices switchable between superconducting and normal states
- H10N 69/00: Integrated devices, or assemblies of multiple devices, comprising at least one superconducting element covered by group H10N60/00
- H10W 42/20: protecting against electromagnetic or particle radiation, e.g. light, X-rays, gamma-rays or electrons
- H10N 60/35: Cryotrons
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

The various embodiments described herein include methods, devices, and systems for implementing logic gates. In one aspect, a circuit includes: (1) a superconducting component having a plurality of alternating narrow and wide portions; (2) a plurality of heat sources, each heat source of the plurality of heat sources coupled to a corresponding narrow portion of the plurality of alternating narrow and wide portions and configured to selectively provide heat to the corresponding narrow portion; (3) a bias current source coupled to each narrow portion of the plurality of alternating narrow and wide portions; and (4) an output node adapted to output a respective current while the plurality of superconducting components is in the non-superconducting state.

## Claims

### Claim 1

An electric circuit, comprising:
a superconducting component having a plurality of alternating narrow and wide portions;
a plurality of current sources, each current source of the plurality of current sources coupled to a corresponding narrow portion of the plurality of alternating narrow and wide portions and configured to selectively provide a first current to the corresponding narrow portion;
a bias current source coupled to each narrow portion of the plurality of alternating narrow and wide portions, the bias current source configured to selectively provide:
a second current adapted to bias each narrow portion of the plurality of alternating narrow and wide portions such that a combination of the second current and the first current from any current source of the plurality of current sources causes each narrow portion of the plurality of alternating narrow and wide portions to transition from a superconducting state to a non-superconducting state; and
a third current adapted to bias each narrow portion of the plurality of alternating narrow and wide portions such that (1) a combination of the third current and the first current from each current source of the plurality of current sources causes each narrow portion of the plurality of alternating narrow and wide portions to transition from the superconducting state to the non-superconducting state, and (2) a combination of the third current and the first current from each current source of only a subset of the plurality of current sources does not cause one or more narrow portions of the plurality of alternating narrow and wide portions to transition to the non-superconducting state; and
an output node adapted to output a respective current while each narrow portion of the plurality of alternating narrow and wide portions is in the non-superconducting state.

### Claim 2 (depends on 1)

The electric circuit of claim 1, wherein the superconducting component comprises a thin film of superconducting material.

### Claim 3 (depends on 1)

The electric circuit of claim 1, wherein the electric circuit consists essentially of a single metal layer.

### Claim 4 (depends on 1)

The electric circuit of claim 1, wherein each current source of the plurality of current sources and the bias current source are coupled to the superconducting component via a single metal layer.

### Claim 5 (depends on 1)

The electric circuit of claim 1, wherein each current source of the plurality of current sources and the bias current source are coupled to the superconducting component such that no metal layers overlap the superconducting component.

### Claim 6

An electric circuit, comprising:
a superconducting component having a plurality of alternating narrow and wide portions;
a plurality of heat sources, each heat source of the plurality of heat sources coupled to a corresponding narrow portion of the plurality of alternating narrow and wide portions and configured to selectively provide heat to the corresponding narrow portion;
a bias current source coupled to each narrow portion of the plurality of alternating narrow and wide portions, the bias current source configured to selectively provide:
a first current adapted to bias each narrow portion of the plurality of alternating narrow and wide portions such that a combination of the first current and heat from any heat source of the plurality of heat sources causes each narrow portion of the plurality of alternating narrow and wide portions to transition from a superconducting state to a non-superconducting state; and
a second current adapted to bias each narrow portion of the plurality of alternating narrow and wide portions such that (1) a combination of the second current and heat from each heat source of the plurality of heat sources causes each narrow portion of plurality of alternating narrow and wide portions to transition from the superconducting state to the non-superconducting state, and (2) a combination of the second current and heat from each heat source of only a subset of the plurality of heat sources does not cause one or more narrow portions of plurality of alternating narrow and wide portions to transition to the non-superconducting state; and
an output node adapted to output a respective current while each narrow portion of plurality of alternating narrow and wide portions is in the non-superconducting state.

### Claim 7 (depends on 6)

The electric circuit of claim 6, wherein the superconducting component comprises a thin film of superconducting material.

### Claim 8 (depends on 6)

The electric circuit of claim 6, wherein the plurality of heat sources is electrically-isolated from the superconducting component.

### Claim 9 (depends on 6)

The electric circuit of claim 6, wherein the bias current source is configured to selectively operate the electrical circuit in any one of a logical OR configuration, a logical AND configuration, and a logical majority-gate configuration.

### Claim 10 (depends on 6)

The electric circuit of claim 6, wherein each heat source of the plurality of heat sources and the bias current source are coupled to the superconducting component such that no metal layers overlap the superconducting component.

### Claim 11 (depends on 6)

The electric circuit of claim 6, wherein the superconducting component and the plurality of heat sources are patterned from a single thin film.

### Claim 12

A method, comprising:
at an electric circuit having a plurality of circuits coupled in parallel with one another, each circuit of the plurality of circuits including a respective superconducting component of a plurality of superconducting components:
operating the electric circuit in a first mode by providing a first bias current to the electric circuit;
while operating the electric circuit in the first mode:
providing a first input current to any of the plurality of superconducting components; and
obtaining a first output in response to providing the first input current, the first output indicative of the plurality of superconducting components being in a non-superconducting state; and
transitioning the electric circuit from operating in the first mode to operating in a second mode by providing a second bias current to the electric circuit; and
while operating the electric circuit in the second mode:
providing the first input current to each of one or more superconducting components, less than all, of the plurality of superconducting components;
obtaining a second output in response to providing the first input current to each of one or more superconducting components, but less than all, of the plurality of superconducting components, the second output indicative of at least one of the plurality of superconducting components being in a superconducting state:
providing the first input current to each superconducting component of the plurality of superconducting components; and
obtaining a third output in response to providing the first input current to each superconducting component of the plurality of superconducting components, the third output indicative of the plurality of superconducting components being in the non-superconducting state.

### Claim 13 (depends on 12)

The method of claim 12, wherein the electric circuit functions as a logical OR gate while operating in the first mode and functions as a logical AND gate while operating in the second mode.

### Claim 14 (depends on 12)

The method of claim 12, wherein the second bias current is greater than the first bias current.

### Claim 15 (depends on 12)

The method of claim 12, wherein the first bias current and the second bias current are each below respective superconducting current thresholds of the plurality of superconducting components.

### Claim 16 (depends on 12)

The method of claim 12, wherein the combination of the second bias current and the first input current causes an avalanche effect for the plurality of superconducting components.

### Claim 17 (depends on 12)

The method of claim 12, further comprising transitioning the electric circuit from operating in the second mode to operating in the first mode by ceasing to provide the second bias current and providing the first bias current.

### Claim 18 (depends on 12)

The method of claim 12, further comprising operating the electric circuit in a third mode by providing a third bias current.

### Claim 19 (depends on 18)

The method of claim 18, wherein the third mode corresponds to a logical majority gate mode, and wherein the third bias current is between the first bias current and the second bias current.

### Claim 20 (depends on 12)

The method of claim 12, wherein the plurality of superconducting components comprise narrow portions of a thin film of superconducting material having alternating narrow and wide portions.