Turning the Tables in Hybrid Classical-Quantum Systems—Classical Optimization of Quantum Algorithms: Plenary Talk

Spurred by recent technical advances that have brought us closer to integrating many qubits, quantum technologies promise to revolutionize computation and communication. The applications that capitalize on quantum computing's superior power are vast: quantum communications (with quantum key distribution as the only protocol that guarantees unconditionally secure key growth and quantum teleportation as the driving force of the future quantum internet), quantum algorithms (providing polynomial solutions to NP problems in classical computation), quantum simulation (with accurate molecular quantum dynamics delivering a massive boost in fields such as drug design), and quantum sensors (offering support for gravimetry, seismology, and civil engineering). This talk will present the specificity of quantum computation and stress what makes it more powerful than classical computation, particularly in algorithms; at the same time, it will present the technological limitations that call for hybrid classical-quantum solutions. The primary approach in designing such hybrid algorithms is to bring a quantum optimization or speedup to a classical method. This presentation argues for a different strategy, namely the classical optimization of a quantum algorithm, and illustrates this concept with an application of Grover's algorithm.