Qubits by selective laser-modulated deposition

Patent metadata

Field	Value
Publication number	US-10170680-B2
Application number	US-201514856274-A
Country	US
Kind code	B2
Filing date	Sep 16, 2015
Priority date	Sep 16, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A method for adjusting a qubit includes measuring a qubit characteristic of a qubit device and computing a modification to correct the qubit characteristic. A geometry of a shunt capacitor is adjusted using a laser direct write process. The qubit characteristic is verified.

First claim

The invention claimed is:

1. A method for adjusting a qubit, comprising:
measuring a qubit characteristic of a qubit device;
computing a modification to correct the qubit characteristic;
adjusting a geometry of a shunt capacitor using a laser direct write process; and
verifying that the qubit characteristic has been corrected by the adjusting of the geometry.

2. The method as recited in claim 1 , further comprising, repeating the steps until the qubit characteristic has been corrected.

3. The method as recited in claim 1 , wherein adjusting the geometry includes adding material to the shunt capacitor.

4. The method as recited in claim 3 , wherein adding material to the shunt capacitor includes employing an argon laser with aluminum methylamine hydride to deposit aluminum on the shunt capacitor.

5. The method as recited in claim 1 , wherein adjusting the geometry includes removing material from the shunt capacitor.

6. The method as recited in claim 1 , wherein adjusting the geometry includes modifying material of the shunt capacitor.

7. The method as recited in claim 6 , wherein modifying material of the shunt capacitor includes oxidizing or nitriding the material of the shunt capacitor.

8. The method as recited in claim 1 , wherein the qubit device includes a Josephson junction.

9. The method as recited in claim 1 , wherein adjusting the geometry includes forming a correction pattern at a position of minimum electric field participation so that reduction of qubit device coherence is minimized.

10. A method for adjusting a qubit, comprising:
fabricating a qubit device, wherein the qubit device includes a Josephson junction;
measuring a qubit characteristic of a qubit device;
computing a modification to correct the qubit characteristic to achieve a needed performance for the qubit device;
adjusting a geometry of a shunt capacitor, post production, using a laser direct write process;
verifying that the qubit characteristic has been changed by the adjusting of the geometry; and
repeating until the qubit characteristic has been corrected.

11. The method as recited in claim 10 , wherein adjusting the geometry includes adding material to the shunt capacitor.

12. The method as recited in claim 11 , wherein adding material to the shunt capacitor includes employing an argon laser with aluminum methylamine hydride to deposit aluminum on the shunt capacitor.

13. The method as recited in claim 10 , wherein adjusting the geometry includes removing material from the shunt capacitor.

14. The method as recited in claim 10 , wherein adjusting the geometry includes modifying material of the shunt capacitor.

15. The method as recited in claim 14 , wherein modifying material of the shunt capacitor includes oxidizing or nitriding the material of the shunt capacitor.

16. The method as recited in claim 10 , wherein adjusting the geometry includes forming a correction pattern at a position of minimum electric field participation so that reduction of qubit device coherence is minimized.

17. A qubit device, comprising:
a Josephson junction; and
a shunt capacitor coupled to the Josephson junction, the shunt capacitor including a shape modified, post-production, to adjust a qubit characteristic for the qubit device.

18. The qubit device as recited in claim 17 , wherein the shape modified includes material added to or subtracted from the shunt capacitor using a laser.

19. The qubit device as recited in claim 17 , wherein the shape modified includes modified material of the shunt capacitor.

20. The qubit device as recited in claim 17 , wherein the shape modified includes a correction pattern at a position of minimum electric field participation so that reduction of qubit device coherence is minimized.

Assignees

• IBM

Inventors

• Abraham David W
• Gambetta Jay M
• Rothwell Mary B

Classifications

• G06N99/002

  Physics · mapped topic

• H01L29/7613

  Electricity · mapped topic

• H01L39/24 Primary

  Electricity · mapped topic

• H10D30/402

  Single electron transistors; Coulomb blockade transistors · CPC title

• G06N10/40

  Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control · CPC title