ANNEALING-BASED VARIATIONAL QUANTUM PROCESSORS

Quantum annealers are devices that prepare the ground state of complex many-body quantum models. These quantum processors have a large transformative power -they can solve real-life problems of interest: scheduling, navigation, quantum chemistry, and many others-, and important technological advantages over universal quantum computers -no need for error correction nor accurate gate operations- that make such processors potentially simpler to design, build, and control. The goal of this consortium is to beat the limitations of current annealing devices regarding heating, noise and dephasing by building and operating a coherent quantum annealer based on superconducting qubits with high connectivity, tuneable interactions and long coherence times. The radical vision in AVaQus is to demonstrate the capacity of quantum annealers to act as general-purpose quantum simulators of spin models and non-universal quantum computers for variational algorithms. Our proposal banks on the progress of superconducting quantum technology and on well-developed superconducting qubit circuitry. However, unlike quantum computing, coherent quantum annealers are in earlier stages of development and this project represents a ramp-up effort to develop the core technology -qubits, tuneable couplings, layouts, controls- and ideas for sustainable scalability. Consequent with this vision, AVaQus brings together excellent European research groups and small to medium-sized enterprises, under the common goal of developing an integrated, small-size and fully-functional quantum processor that demonstrates coherent quantum annealing with 5 qubits fully connected in a multi-coupler network. We will also develop comprehensive real-life optimization problems and simulations in quantum chemistry, spin models and finance that are solved by our small-scale quantum annealer, create methods for validation and certification, and provide a route towards achieving a quantum advantage in larger-scale devices.