5 papers
Compact graphs and quantum automorphisms
Pedro Baptista, Gabriel Coutinho, Chris Godsil +1
Compact graphs are graphs for which the fractional automorphism polytope has no genuinely fractional vertices. This paper proposes a quantum analogue of this idea by evaluating the…
A SWAP-free Framework for QAOA
Thiago Assis, Pedro Baptista, Laila Lopes +2
The performance of the Quantum Approximate Optimization Algorithm (QAOA) on noisy intermediate-scale quantum (NISQ) devices is strongly limited by sparse qubit connectivity. When i…
Unexpected Averages of Mixing Matrices
Pedro Baptista, Gabriel Coutinho, Vitor Marques
The (standard) average mixing matrix of a continuous-time quantum walk is computed by taking the expected value of the mixing matrices of the walk under the uniform sampling distri…
Quantum Walks in the Normalized Laplacian
Gabriel Coutinho, Pedro Ferreira Baptista
We provide a characterization of perfect state transfer in a quantum walk whose Hamiltonian is given by the normalized Laplacian. We discuss a connection between classical random w…
Irrational quantum walks
Gabriel Coutinho, Pedro Ferreira Baptista, Chris Godsil +2
The adjacency matrix of a graph G is the Hamiltonian for a continuous-time quantum walk on the vertices of G. Although the entries of the adjacency matrix are integers, its eigenva…