Compact Control System for Superconducting Qubits

Thomas Ortlepp, Anna Reinhardt, Taghrid Haddad +1 more

Quantum technologies are today regarded as one of the key technologies with huge implications to technological, economic and social developments in the next decades. Among the different platforms, superconducting implementations represent one of the most promising and are therefore pursued by several research institutions but also by numerous high-tech companies. Current research focusses e.g. on scaling towards a large number of qubits needed for practical implementations of this technology. Amongst the various realizations, adiabatic quantum flux parametron (AQFP) circuits have shown lowest power dissipation reaching Landauer limit. The operation of AQFP circuits down to mK temperature has been recently demonstrated. We will present a new concept for a digital control circuit based on the microwave pulse patters generated by single flux quantum circuits operating at mK temperatures. We discuss the circuit operation and the integration together with superconducting qubits to a compact and scalable approach for multi-Qubit control by digital pulse patterns.

Irfan A. Siddiqi

Yasunobu Nakamura

Julia Zotova, S. V. Sanduleanu, Gleb Fedorov +3 more

We demonstrate control and readout of a superconducting artificial atom based on a transmon qubit using a compact lumped-element resonator. The resonator consists of a parallel-plate capacitor with a wire geometric inductor. The footprint of the resonators is about 200 × 200 μm2, which is similar to the standard transmon size and one or two orders of magnitude more compact in the occupied area compared to coplanar waveguide resonators. We observe coherent Rabi oscillations and obtain time-domain properties of the transmon. The work opens a door to miniaturize essential components of superconducting circuits and to further scale up quantum systems with superconducting transmons.

Jiawei Zhang, Xuandong Sun, Zechen Guo +17 more

As superconducting quantum computing continues to advance at an unprecedented pace, there is a compelling demand for the innovation of specialized electronic instruments that act as crucial conduits between quantum processors and host computers. Here, we introduce a Microwave Measurement and Control System (M2CS) dedicated for large-scale superconducting quantum processors. M2CS features a compact modular design that balances overall performance, scalability, and flexibility. Electronic tests of M2CS show key metrics comparable to commercial instruments. Benchmark tests on transmon superconducting qubits further show qubit coherence and gate fidelities comparable to state-of-the-art results, confirming M2CS's capability to meet the stringent requirements of quantum experiments run on intermediate-scale quantum processors. The system's compact and scalable design offers significant room for further enhancements that could accommodate the measurement and control requirements of over 1000 qubits, and can also be adopted to other quantum computing platforms such as trapped ions and silicon quantum dots. The M2CS architecture may also be applied to wider range of scenarios, such as microwave kinetic inductance detectors, as well as phased array radar systems.

William D. Oliver