title: Four-junction superconducting circuit.
abstract: We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit.
authors.affiliation: Department of Physics, Fudan University, Shanghai 200433, China.|Beijing Computational Science Research Center, Beijing 100193, China.
authors.forename: Yueyin
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Department of Physics, Fudan University, Shanghai 200433, China.|Beijing Computational Science Research Center, Beijing 100193, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: School of Science, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: He
authors.affiliation: Beijing Computational Science Research Center, Beijing 100193, China.|Institute of Microelectronics, Department of Microelectronics and Nanoelectronics and Tsinghua National Laboratory of Information Science and Technology, Tsinghua University, Beijing 100084, China.
authors.forename: Tie-Fu
authors.initials: TF
authors.lastname: Li
authors.affiliation: Beijing Computational Science Research Center, Beijing 100193, China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: You