Flux-insensitive qubit from a split transmon shunted with a Josephson junction

被引：0

作者：

Geng, Xiao ^{[1
,2
]}

Jiang, Linpan ^{[1
,2
]}

Cheng, Mingjun ^{[1
,2
]}

Liu, Jianshe ^{[1
,2
]}

Chen, Wei ^{[1
,2
,3
]}

机构：

[1] Tsinghua Univ, Sch Integrated Circuits, Lab Superconducting Quantum Informat Proc, Beijing 100084, Peoples R China

[2] Beijing Natl Res Ctr Informat Sci & Technol, Beijing 100084, Peoples R China

[3] Tsinghua Univ, Beijing Innovat Ctr Future Chips, Beijing 100084, Peoples R China

来源：

PHYSICAL REVIEW A | 2024年 / 110卷 / 06期

关键词：

Critical current density (superconductivity) - Fault tolerant computer systems - Josephson junction devices - Photons - Quantum electronics - Quantum noise - Quantum optics - Qubits - Shellfish - Superconducting fault current limiters;

D O I：

10.1103/PhysRevA.110.062607

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Split transmons have been widely used in making quantum processors for building scalable and fault-tolerant superconducting quantum computers. With tunable external flux threading the superconducting quantum interference devices (SQUIDs) of qubits, split transmons have a degree of freedom for tuning frequencies but introduce flux noise as an important dephasing factor at the same time. Here, an improved version of a transmon is proposed and is called a "triple-Josephson-junction transmon" (tri-JJ transmon). A tri-JJ transmon is obtained by shunting another Josephson junction to the SQUID of a split transmon, which can produce much more different local minima and maxima of qubit frequencies tuned by external flux as "sweet spots" than those of split transmons. The first-order effect of the flux noise at the sweet spots can be eliminated and the corresponding pure-dephasing times are estimated as about 200 mu s by considering only critical current noise. Tri-JJ transmons are compatible with the process and the protocol of control and measurement of split transmons and can be competitive candidates for constructing a high-performance superconducting quantum processor.

引用

页数：19