Wednesday 29 April 2026 at 11am (UK Time, room: KENSR1)
Superconducting quantum circuits are among the most popular hardware platforms to build quantum technologies. Those superconducting circuits have many quantum degrees of freedom that are usually not taken into account for technological applications. This talk is all about those higher energy eigenstates that are neglected. We will first show how they seriously impact qubit-qubit interactions when going to the strong coupling regime [1,2]. Then, we will comment on a couple of applications where one takes advantage of those extra higher-energy states. In the first application, we will construct a qutrit with a very long coherence time [3] while, in the second one, we will explain a superconducting quantum reservoir computer that performs statistical classification tasks [4].
[1] Ultrastrong capacitive coupling of flux qubits. M Hita-Pérez, G Jaumà, M Pino, JJ García-Ripoll PRApp (2022)
[2] Low crosstalk modular flip-chip architecture for coupled superconducting qubits. S Ihssen et al. Applied Physics Letters (2025)
[3] Bound states in the continuum in a fluxonium qutrit. M Hita-Pérez, PA Orellana, JJ García-Ripoll, M Pino PRA (2022)
[4] Quantum Reservoir Computing for Statistical Classification in a Superconducting Quantum Circuit. JJ Prieto-Garcia, AG del Pozo-Martín, M Pino
ArXiv (2026)