Construction of two-qubit logical gates by transmon qubits in a three-dimensional cavity

• 来源期刊: 中国物理B（英文版）
• 关键词: 3D transmon qubit qubit–qubit coupling coherent state exchange Rabi-like oscillation
• 年，卷（期）: 2018,（8）
• 页码范围: 280-284
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/8/084207

摘要

We report the implementation of qubit–qubit coupling in a three-dimensional (3D) cavity, using the exchange of virtual photons, to realize logical operations. We measure single photon and multi-photon transitions in this qubit–qubit coupling system and obtain its energy avoided-crossing spectrum. With ac-Stark effect, fast control of the qubits is achievedto tune the effective coupling on and off and the state-swap gate√SWAP is successfully constructed. Moreover, using two-photon transition between the ground state and doubly excited states, a kind of two-photon Rabi-like oscillation isobserved. A quarter period of this oscillation corresponds to the logical gate√bSWAP, which is used for generating Bell states. √bSWAP and√iSWAP are the foundations of future preparation of two-qubit Bell states and realization of CNOT gate.