Quantum technologies allow for fully novel schemes of hybrid computing. We employ modern segmented ion traps. I will sketch architectures, the required trap technologies and fabrication methods, control electronics for quantum register reconfigurations, and recent improvements of qubit coherence and gate performance. Currently gate fidelities of 99.995% (single bit) and 99.8% (two bit) are reached. We are implementing a reconfigurable qubit register and have realized multi-qubit entanglement [1] and fault-tolerant syndrome readout [2] in view for topological quantum error correction [3] and realize user access to quantum computing [4]. The setup allows for mid-circuit measurements and real-time control of the algorithm. We are currently investigating various applications, including variational quantum eigensolver approaches for chemistry or high energy relevant models, and measurement-based quantum computing.

The quantum technology allows for implementing quantum thermodynamics processes and work engine cycles [5,6]. We have also realized a scheme to detect heat leaks in a quantum circuit [7], study quantum corrections to the fluctuation-dissipation relation [8].

[1] Kaufmann et al, Phys. Rev. Lett. 119, 150503 (2017)

[2] Hilder et al, Phys. Rev. X.12.011032 (2022)

[3] Bermudez et al, Phys. Rev. X 7, 041061 (2017)

[4] https://iquan.physik.uni-mainz.de/

[5] Rossnagel et al, Science 352, 325 (2016)

[6] Lindenfels et al,  Phys. Rev. Lett. 123, 080602 (2019)

[7] Pijn et at, Phys. Rev. Lett. 128 110601 (2022)

[8] Onishchenko et al, arXiv:2207.14325