title: Generation of macroscopic Schrödinger cat state in diamond mechanical resonator.
abstract: We propose a scheme to generate macroscopic Schrödinger cat state (SCS) in diamond mechanical resonator (DMR) via the dynamical strain-mediated coupling mechanism. In our model, the direct coupling between the nitrogen-vacancy (NV) center and lattice strain field enables coherent spin-phonon interactions in the quantum regime. Based on a cyclic Δ-type transition structure of the NV center constructed by combining the quantized mechanical strain field and a pair of external microwave fields, the populations of the different energy levels can be selectively transferred by controlling microwave fields, and the SCS can be created by adjusting the controllable parameters of the system. Furthermore, we demonstrate the nonclassicality of the mechanical SCS both in non-dissipative case and dissipative case. The experimental feasibility and challenge are justified using currently available technology.
authors.affiliation: National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Qizhe
authors.initials: Q
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: Wanli
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Physics, Shaoguan University, Shaoguan, Guangdong 512005, China.
authors.forename: Changyong
authors.initials: C
authors.lastname: Chen
authors.affiliation: Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Zhangqi
authors.initials: Z
authors.lastname: Yin