title: Engineering entangled microwave photon states through multiphoton interactions between two cavity fields and a superconducting qubit.
abstract: It has been shown that there are not only transverse but also longitudinal couplings between microwave fields and a superconducting qubit with broken inversion symmetry of the potential energy. Using multiphoton processes induced by longitudinal coupling fields and frequency matching conditions, we design a universal algorithm to produce arbitrary superpositions of two-mode photon states of microwave fields in two separated transmission line resonators, which are coupled to a superconducting qubit. Based on our algorithm, we analyze the generation of evenly-populated states and NOON states. Compared to other proposals with only single-photon process, we provide an efficient way to produce entangled microwave photon states when the interactions between superconducting qubits and microwave fields are in the strong and ultrastrong regime.
authors.affiliation: Institute of Microelectronics, Tsinghua University, Beijing, 100084, China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: Institute of Microelectronics, Tsinghua University, Beijing, 100084, China.
authors.forename: Changqing
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Institute of Microelectronics, Tsinghua University, Beijing, 100084, China.|Tsinghua National Laboratory for Information Science and Technology (TNList), Beijing 100084, China.
authors.forename: Yu-xi
authors.initials: YX
authors.lastname: Liu