AQC 2016 - Building Quantum Annealer v2.0

A Google TechTalk, June 28, 2016, presented by Yu Chen (Google) ABSTRACT: Quantum annealer, constructed from an array of coupled flux qubits, represents an analog approach to build a quantum computer. In Quantum A.I. Lab, we are working on building an enhanced-performance quantum annealer - quantum annealer v2.0. We introduce the "fluxmon" flux qubit as the building block of quantum annealer v2.0. With the capacitance and inductance provided by a coplanar waveguide, the fluxmon qubit design balances between coherence and coupling. Utilizing a microwave control and readout, we were able to characterize single-qubit performance and discovered that the qubit decoherence is dominated by 1/f flux noise over a wide range of frequencies. Meanwhile, with the linear inductance distributed over a macroscopic length scale, we discuss that the fluxmon design allows for GHz-scale coupling for multiple qubits, suitable for highly connected annealer architectures. Presented at the Adiabatic Quantum Computing Conference, June 26-29, 2016, at Google's Los Angeles office.