Implementing a quantum computer at the circuit level has emerged as an important field of research recently. An important topic of building a general-purpose quantum computer is to implement classical Boolean logic using quantum gates and devices. Since the Toffoli gate is universal in classical Boolean logic, any classical combinational circuit can be implemented by the straightforward replace...

We have designed and operated a circuit based on a large-area current-biased Josephson junction whose two lowest energy quantum levels are used to implement a solid-state qubit. The circuit allows measurement of the qubit states with a fidelity of 85% while providing sufficient decoupling from external sources of relaxation and decoherence to allow coherent manipulation of the qubit state, as d...

The synthesis of quantum circuits is a complex problem even for circuits with a small number of lines. At present, optimal synthesis is intractable and heuristic methods must be employed. In this paper, we consider the use of templates to simplify a quantum circuit initially found by other means. The templates tool presented here is a general approach to reversible and quantum circuit simplific...

One-way measurement based quantum computations (1WQC) may describe unitary transformations, via a composition of CPTP maps which are not all unitary themselves. This motivates the following decision problems: Is it possible to determine whether a “quantum-to-quantum” 1WQC procedure (having non-trivial input and output subsystems) performs a unitary transformation? Is it possible to describe pre...

We demonstrate a photonic circuit with integrated long-lived quantum memories. Pre-selected quantum nodes diamond micro-waveguides containing single, stable, and negatively charged nitrogen vacancy centers are deterministically integrated into low-loss silicon nitride waveguides. Each quantum memory node efficiently couples into the single-mode waveguide (> 1 Mcps collected into the waveguide) ...

We study the effects of entanglement and control parameters on symmetry energy landscape optimization performance variational quantum circuit. Through a systematic analysis Hessian spectrum, we characterize local geometry at random point along an trajectory. argue that decreasing entangling capability increasing number circuit have same qualitative effect eigenspectrum. Both low-entangling abun...