A measurement-based variational quantum eigensolver

          @misc{ pirsa_PIRSA:20110031,
            doi = {10.48660/20110031},
            url = {https://pirsa.org/20110031},
            author = {Dellantonio, Luca},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {A measurement-based variational quantum eigensolver},
            publisher = {Perimeter Institute},
            year = {2020},
            month = {nov},
            note = {PIRSA:20110031 see, \url{https://pirsa.org}}
          }
          

Abstract

In this talk I will speak about the meeting point of two models that have raised interest in the community in the last years. From one side, we looked at measurement-based quantum computing (MBQC), which is an alternative to circuit-based quantum computing. Instead of modifying a state via gates, MBQC achieves the same result by measuring auxiliary qubits in a graph. From the other side, we considered variational quantum eigensolvers (VQEs), that are one of the most successful tools for exploiting quantum computers in the NISQ era. In our work, we present two measurement-based VQE schemes. The first introduces a new approach for constructing variational families. The second provides a translation of circuit-based to measurement-based schemes. Both schemes offer problem-specific advantages in terms of the required resources and coherence times. We apply them, respectively, to the Schwinger model and the two-dimensional Z(2) lattice gauge theory.