# Quantum Devices: Research directions at CESQ

Engineered quantum devices are mesoscopic physical systems which leverage quantum effects for new and improved functionality.

*Open questions:*

- Can we deliberately engineer quantum systems for robust quantum behavior?
- What are the real world applications of quantum devices?

*Research topics:*

*Engineered quantum systems*

By tuning interactions between quantum systems and their environment it is possible to engineer robust quantum behavior. CESQ researchers investigate schemes for generating nonreciprocity, e.g., to improve the fidelity of entangled states, and non-trivial quantum correlations for quantum sensing and computing

*Molecular qudits*

CESQ researchers have demonstrated the read-out of a coupled molecular multi-level quantum system, carried by a single Tb2Pc3 molecular magnet. With two magnetic centres, this molecular magnet architecture permits a 16-fold dimensional Hilbert space, opening the possibility of performing more complex quantum algorithms.

*Hybrid quantum systems*

CESQ researchers develop theory and applications of hybrid quantum systems which combine different types of quantum degrees of freedom, such as electronic, magnetic excitations, with optical photons and photons.

*Photon spin interfaces*

Rare-earth ions are promising solid-state systems for building light–matter interfaces at the quantum level. CESQ researchers study mononuclear Europium(III) complexes, in which the nuclear spins can be read-out and manipulated by photons forming an effective photon-spin interface with potential for distributed quantum computing.