title: Experimental realization of universal geometric quantum gates with solid-state spins.
abstract: Experimental realization of a universal set of quantum logic gates is the central requirement for the implementation of a quantum computer. In an 'all-geometric' approach to quantum computation, the quantum gates are implemented using Berry phases and their non-Abelian extensions, holonomies, from geometric transformation of quantum states in the Hilbert space. Apart from its fundamental interest and rich mathematical structure, the geometric approach has some built-in noise-resilience features. On the experimental side, geometric phases and holonomies have been observed in thermal ensembles of liquid molecules using nuclear magnetic resonance; however, such systems are known to be non-scalable for the purposes of quantum computing. There are proposals to implement geometric quantum computation in scalable experimental platforms such as trapped ions, superconducting quantum bits and quantum dots, and a recent experiment has realized geometric single-bit gates in a superconducting system. Here we report the experimental realization of a universal set of geometric quantum gates using the solid-state spins of diamond nitrogen-vacancy centres. These diamond defects provide a scalable experimental platform with the potential for room-temperature quantum computing, which has attracted strong interest in recent years. Our experiment shows that all-geometric and potentially robust quantum computation can be realized with solid-state spin quantum bits, making use of recent advances in the coherent control of this system.
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: C
authors.initials: C
authors.lastname: Zu
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: W-B
authors.initials: WB
authors.lastname: Wang
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: L
authors.initials: L
authors.lastname: He
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: W-G
authors.initials: WG
authors.lastname: Zhang
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Dai
authors.affiliation: Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.affiliation: 1] Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, China [2] Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: L-M
authors.initials: LM
authors.lastname: Duan