Methods for annealing qubits with an antenna chip

Patent metadata

Field	Value
Publication number	US-11765986-B2
Application number	US-202117230607-A
Country	US
Kind code	B2
Filing date	Apr 14, 2021
Priority date	Aug 28, 2018
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

Systems, computer-implemented methods, and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a first antenna can be positioned above a superconducting qubit chip having a first Josephson junction and a second Josephson junction. The first antenna can direct a first electromagnetic wave toward the first Josephson junction. A first length of a first defined vertical gap, between the first antenna and the superconducting qubit chip, can be sized to cause the first electromagnetic wave to circumscribe a first set of one or more capacitor pads of the first Josephson junction, thereby annealing the first Josephson junction, without annealing the second Josephson junction. In another example, the first length of the first defined vertical gap can be a function of a model of the first electromagnetic wave as a cone, wherein the cone originates from the first antenna and extends toward the superconducting qubit chip.

First claim

What is claimed is:

1. A system, comprising:
a superconducting qubit chip having a first qubit, with a first Josephson junction, and a second qubit, with a second Josephson junction;
an antenna chip positioned above the superconducting qubit chip;
a first antenna on the antenna chip and that directs a first electromagnetic wave toward the first qubit; and
a first defined vertical gap, between the first antenna and the superconducting qubit chip, wherein a first length of the first defined vertical gap is sized to cause the first electromagnetic wave to circumscribe a first set of one or more capacitor pads of the first qubit, thereby annealing the first Josephson junction of the first qubit.

2. The system of claim 1 , wherein the first length of the first defined vertical gap is a function of a model of a radiation pattern of the first electromagnetic wave as a cone.

3. The system of claim 2 , wherein the cone originates from the first antenna on the antenna chip and extends toward the superconducting qubit chip.

4. The system of claim 2 , wherein the first length of the first defined vertical gap is approximately equal to a height of the cone.

5. The system of claim 2 , wherein a base of the cone circumscribes the first set of one or more capacitor pads.

6. The system of claim 4 , wherein an apex angle of the cone is approximately equal to a three-decibel angular beam width of a main lobe of the radiation pattern of the first electromagnetic wave.

7. The system of claim 1 , further comprising:
one or more spacers located in the first defined vertical gap and between the antenna chip and the superconducting qubit chip, wherein a height of the one or more spacers is approximately equal to the first length of the first defined vertical gap.

8. The system of claim 1 , further comprising:
a second antenna on the antenna chip and that directs a second electromagnetic wave toward the second qubit; and
a second defined vertical gap, between the second antenna and the superconducting qubit chip, wherein a second length of the second defined vertical gap is sized to cause the second electromagnetic wave to circumscribe a second set of one or more capacitor pads of the second qubit, thereby annealing the second Josephson junction of the second qubit.

9. The system of claim 8 , wherein the first antenna directs the first electromagnetic wave for a first time period and the second antenna directs the second electromagnetic wave for a second time period, wherein the first time period and the second time period are overlapping.

10. The system of claim 1 , wherein a first wavelength of the first electromagnetic wave is adjusted based on a first physical dimension of the first set of one or more capacitor pads.

11. The system of claim 10 , wherein the first wavelength is greater than or approximately equal to four times the first physical dimension of the first set of one or more capacitor pads.

12. A device, comprising:
a superconducting qubit chip having a first Josephson junction and a second Josephson junction;
an antenna chip above the superconducting qubit chip; and
a micromanipulator, a piezocontroller, or a temporary attachment that positions the antenna chip above the superconducting qubit chip, with a defined vertical gap between the antenna chip and the superconducting qubit chip, wherein a length of the defined vertical gap is sized by the micromanipulator, piezocontroller, or temporary attachment to cause the first electromagnetic wave to circumscribe the first Josephson junction, thereby annealing the first Josephson junction.

13. The device of claim 12 , wherein the length of the defined vertical gap is also sized to cause the second electromagnetic wave to circumscribe the second Josephson junction, thereby annealing the second Josephson junction.

14. The device of claim 12 , further comprising:
a first antenna on the antenna chip and that emits a first electromagnetic wave toward the first Josephson junction.

15. The device of claim 14 , further comprising:
a second antenna on the antenna chip and that emits a second electromagnetic wave toward the second Josephson junction.

16. The device of claim 13 , wherein the length of the defined vertical gap is approximately equal to a height of a cone, a base of which cone circumscribes the first Josephson junction.

17. The device of claim 16 , wherein the cone comprises an apex angle approximately equal to a three-decibel angular beam width of a main lobe of a radiation pattern of the first electromagnetic wave.

Assignees

• IBM

Inventors

• Topaloglu Rasit Onur
• Rosenblatt Sami

Classifications

• H10D48/3835

  Semiconductor qubit devices comprising a plurality of quantum mechanically interacting semiconductor quantum dots, e.g. Loss-DiVincenzo spin qubits · CPC title

• H10N60/0912 Primary

  of Josephson-effect devices · CPC title

• H10N60/12 Primary

  Josephson-effect devices · CPC title

• B82Y10/00 Primary

  Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic · CPC title

• H01Q1/364

  using a particular conducting material, e.g. superconductor · CPC title