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Pol Forn-Diaz is author of a new publication focused on the opportunity to use acoustic wave filters as a Purcell filter. Using acoustic wave filters, like bulk acoustic wave (BAW) or surface acoustic wave (SAW), versus the current state-of-the-art Purcell filters would provide several advantages: higher isolation of the qubit to the readout frequencies as well as being quite miniaturized compared to usual filter alternatives. In this work a 1.5GHz LiNbO SAW resonator was characterized.

On the 26th of April Alba Torras was invited to present at the Quantum CARLA symposium. This yearly symposium is targeted at students in the initial steps of their careers. There were several stablished researchers and early career scientists showing their careers paths. Alba presented the trajectory of her first year as a research in Quantum Physics and how she decided to pursue a career to become an experimental quantum physicist.

The AVaQus Collaboration held their first in-person meeting on the 20th of April at the Centro de Ciencias Pedro Pascual in Benasque (Spain). Members of IFAE, CNRS, Delft Circuits, KIT, CSIC, HQS, and Qilimanjaro exchanged information on the status of the project and laid the path forward to pursue their respective goals.

IFAE members David López-Núñez, Fabian Zwiehoff, and Pol Forn-Díaz organized the first Spring School on Superconducting Qubits Technology held in Benasque (Spain). The school took place from the 11th to the 21st of April and saw the partecipation of more than 70 members from both research institutions and industry. Quantum computers based on superconducting qubit technology are currently one of the leading platforms in the race towards quantum advantage. As a highly multidisciplinary field, it requires expertise in subjects like quantum optics, microwave engineering, circuit design, nanofabrication, measurement electronics and quantum metrology, as well as cryogenics.

We propose and demonstrate two mitigation methods to attenuate the cosmic muon flux compatible with experiments involving superconducting qubits. Using a specifically-built cosmic muon detector, we find that chips oriented towards the horizon compared to chips looking at the sky overhead experience a decrease of a factor 1.6 of muon counts at the surface. Then, we identify shielded shallow underground sites, ubiquitous in urban environments, where significant additional attenuation, up to a factor 35 for 100-meter depths, can be attained.

The annual APS March Meeting welcomes a diverse international community of over 10,000 scholars to celebrate the frontiers of physics. This year it was held in Las Vegas, Nevada from the 5th to the 10th of March. Three members of QCT attended the conference: Alba Torras-Coloma gave a talk about nitridized aluminum thin films for superconducting technologies. David Lopez Nuñez presented the progress in designing and measuring coherent flux qubits for quantum annealing, while Elia Bertoldo talked about methods to reduce the cosmic muon flux in experiments with superconducting qubits.

The QCT group has recently received funding from two national programs to fund its activities in the coming 3 years. The first project NESQQ (Nanofabrication-Enhanced Superconducting Qubit Quality) is funded through the ‘Plan Complementario’ from the EU NextGen funds. The project is part of a larger-scale program on Quantum Communications led by ICFO. NESQQ will aim at improving qubit quality by intensive fabrication efforts, both studying the addition of novel materials as well as by modifications of the qubit device structure.

On 28th of September 2022 the students from the Quantum Science & Technology Master visited the IFAE laboratories.

On 27th of June 2022 the QCT lab presented its newest achivements during the poster session of the SQA conference held in Finland. David Lopez presented a poster titled “Coherent flux qubits for quantum annealing”. A next milestone in a race for efficent quantum annealing hardware.

The Quantum Computing Technologies (QCT) group congratulates with Queralt Portell, who succesfully defended her Bachelor’s thesis on the London penetration depth in thin aluminum layers. Queralt focused on the fabrication of superconducting resonators and the analysis of the samples. We congratulate her and wish her best of luck in the future!