Superconducting Qubit-Resonator-Atom Hybrid System Deshui Yu 1 , Leong Chuan Kwek 1,2,3,4 , Luigi Amico 1,5,6 , & Rainer Dumke 1,7 1 Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore 2 Institute of Advanced Studies, Nanyang Technological University, 60 Nanyang View, Singapore 639673, Singapore 3 National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Singapore 4 MajuLab, CNRS-UNS-NUS-NTU International Joint Research Unit, UMI 3654, Singapore 5 CNR-MATIS-IMM & Dipartimento di Fisica e Astronomia, Universit´a Catania, Via S. Soa 64, 95127 Catania, Italy 6 INFN Laboratori Nazionali del Sud, Via Santa Sofia 62, I-95123 Catania, Italy 7 Division of Physics and Applied Physics, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore E-mail: rdumke@ntu.edu.sg Abstract. We propose a hybrid quantum system, where an LC resonator inductively interacts with a flux qubit and is capacitively coupled to a Rydberg atom. Varying the external magnetic flux bias controls the flux-qubit flipping and the flux qubit-resonator interface. The atomic spectrum is tuned via an electrostatic field, manipulating the qubit-state transition of atom and the atom-resonator coupling. Different types of entanglement of superconducting, photonic, and atomic qubits can be prepared via simply tuning the flux bias and electrostatic field, leading to the implementation of three-qubit Toffoli logic gate. 1. Introduction The most promising candidates for building a quantum computer include supercon- ducting circuits, flying photonic qubits, and ultracold atoms. The superconducting devices [1, 2, 3, 4, 5, 6], based on Josephson junctions (JJs), own the advantages of flexibility, tunability, scalability, and rapid processing quantum information, but their decoherence times are limited owing to the strong coupling to external fields [7, 8, 9, 10]. The flying qubits [11, 12, 13, 14], due to the nature of transmitting at the speed of light, are usually applied to implement the remote entanglement of spatially separated quan- tum systems. In contrast, the atoms [15, 16, 17, 18] are characterized by the properties of arXiv:1706.09527v1 [physics.atom-ph] 29 Jun 2017