QUNNECT: A Fiber Optic Transceiver For Superconducting Qubits


Research in optical quantum networks and superconducting devices has progressed largely independently so far. While superconducting qubits are ideally suited for on-chip integration and fast processing, they are problematic for quantum communication. No solution exists to connect remote qubits via a room temperature link. The small energy scales in the electrical circuit make the fragile information carriers (single microwave photons) susceptible to interference, thermal noise and losses, which has hindered any significant progress in this direction.

We recently have gained sufficient insight into low loss materials, the required fabrication technology, and the precision measurement techniques necessary to bridge the two worlds, by controlling individual photons and phonons quantum coherently. We are working towards integrating silicon photonics for low-loss fiber optic communication with superconducting circuits for quantum processing on a single microchip. As intermediary transducer we will focus on two approaches:
(1) quantum ground state cooled nanoscale mechanical and
(2) low-loss electro-optic nonlinear circuit elements.

The novelty of our approach in QUNNECT is the tight on-chip integration facilitated by our groups interdisciplinary background in both, superconducting circuits and silicon nanophotonics. Integration will be the key for realizing a low-loss and high-bandwidth transceiver, for preparing remote entanglement of superconducting qubits, and for extending the range of current fiber optic quantum networks.

Team: Alfredo Rueda, William Hease

Hybrid Semiconductor – Superconductor Quantum Devices


Using quantum states of microscopic physical systems for more effective problem solving is not a new idea, but only just now, after many decades of basic research, nanofabrication and quantum control technology have evolved sufficiently to make an attempt to build a microchip-based quantum computer. While it is clear that drastic algorithmic improvements are still needed for useful quantum processing, there is also no consensus about the ideal hardware to use. Very important basic questions are still unanswered. Can we find designs with built-in hardware-protection to extend the coherence times of superconducting qubits further? How can we reliably generate, detect and make use of exotic quasiparticles such as Majorana fermions?

In this project funded by a NOMIS research grant we join forces with the Katsaros group to give answers to these important questions. The goal is to improve the properties of superconducting and semiconducting qubits and to couple them with superconducting bus systems. Such hybrid devices might prove to be the most promising building blocks for future quantum devices.

Team: Matilda Peruzzo, Martin Zemlicka

HOT: Hybrid Optomechanical Technologies


The HOT consortium funded by the European Union Future and Emerging Technology proactive scheme aims to lay the foundation for a new generation of devices, which connect or even contain, several platforms at the nanoscale in a single “hybrid” system. As hybrid interfaces they will allow the exploitation of the unique advantages of each subsystem within a nano-scale footprint, while as integrated hybrid devices they will enable entirely novel functionalities.

A particular focus is to explore hybrid opto- and electro-mechanical devices operating at the physical limits for conversion, synthesis, processing, sensing and measurement of electromagnetic (EM) fields, from radio and microwave frequencies to the terahertz domain. These spectral regions are relevant to the important existing application domains of medicine (e.g. MRI imaging), security (e.g. Radar and THz monitoring), positioning, timing and navigation (oscillators) and for future quantum technology.

Team: Matthias Wulf