5 papers
Dynamical Decoupling using Universal Optimal Tracking
Amit Devra, Emanuel Malvetti, Niklas J. Glaser +7
Dynamical decoupling (DD) is a widely used and resource-efficient technique for error suppression, but conventional DD relies on periodically repeating a short pulse block to refoc…
On the convergence of the variational quantum eigensolver and quantum optimal control
Marco Wiedmann, Daniel Burgarth, Gunther Dirr +3
When does a variational quantum algorithm converge to a globally optimal solution? Despite the large literature around variational approaches to quantum computing, the answer is la…
Randomized Gradient Descents on Riemannian Manifolds: Almost Sure Convergence to Global Minima in and beyond Quantum Optimization
Emanuel Malvetti, Christian Arenz, Gunther Dirr +1
We analyze convergence of gradient-descent methods on Riemannian manifolds. In particular, we study randomization of Riemannian gradient algorithms for minimizing smooth cost funct…
Theory and Experimental Demonstration of Wigner Tomography of Unknown Unitary Quantum Gates
Amit Devra, Léo Van Damme, Frederik vom Ende +2
We investigate the tomography of unknown unitary quantum processes within the framework of a finite-dimensional Wigner-type representation. This representation provides a rich visu…
The Thermomajorization Polytope and Its Degeneracies
Frederik vom Ende, Emanuel Malvetti
Drawing inspiration from transportation theory, in this work we introduce the notions of "well-structured" and "stable" Gibbs states and we investigate their implications for quant…