Evaluating radiation impact on transmon qubits in above and underground facilities

Journal Article · Fri Mar 13 00:00:00 UTC 2026 · EPJ Quant.Technol.

DOI: https://doi.org/10.1140/epjqt/s40507-026-00490-2 · OSTI ID:2376939

De Dominicis, Francesco ^[1]; Roy, Tanay  ^[2]; Mariani, Ambra  ^[3]; Bal, Mustafa  ^[2]; Bonomo, Camilla ^[4]; Casali, Nicola ^[3]; Colantoni, Ivan ^[3]; Crisa, Francesco ^[5]; Cruciani, Angelo ^[3]; Ferroni, Fernando ^[6]; Helis, Dounia L.  ^[7]; Pagnanini, Lorenzo ^[1]; Pettinacci, Valerio ^[3]; Pilipenko, Roman  ^[2]; Pirro, Stefano ^[7]; Puiu, Andrei ^[7]; Ressa, Alberto ^[3]; Romanenko, Alexander  ^[2]; Vignati, Marco ^[4]; van Zanten, David  ^[2] ; Zhu, Shaojiang  ^[2]; Grassellino, Anna  ^[2]; Cardani, Laura ^[3]

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1. GSSI, Aquila; INFN, LNS
2. Fermilab
3. INFN, Rome
4. INFN, Rome; Rome U.
5. IIT, Chicago
6. GSSI, Aquila; INFN, Rome
7. INFN, LNS

Superconducting qubits can be sensitive to energy deposits caused by cosmic rays and ambient radioactivity. While previous studies have explored correlated effects in time and space due to cosmic ray interactions, we present the first direct comparison of a transmon qubit’s performance measured at two distinct sites: the above-ground SQMS facility (Fermilab, US) and the deep-underground Gran Sasso Laboratory (Italy). Despite the stark difference in radiation levels, we observe a similar average qubit relaxation time of approximately 80 microseconds at both locations. To investigate radiation-induced events, we employ a fast decay detection protocol, comparing the relative rates of events between the two environments. Although intrinsic noise remains the dominant source of errors in superconducting qubits, our analysis revealed a significant excess of radiation-induced events for high-coherence transmon qubits operated above-ground. Finally, using γ-ray sources with increasing activity levels, we evaluate the qubit response in a controlled low-background environment.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); GSSI, Aquila; IIT, Chicago; INFN, LNS; INFN, Rome; Rome U.
• Sponsoring Organization: US Department of Energy
• Grant/Contract Number: 89243024CSC000002
• OSTI ID: 2376939
• Report Number(s): FERMILAB-PUB-24-0277-SQMS; oai:inspirehep.net:2791012; arXiv:2405.18355
• Journal Information: EPJ Quant.Technol., Journal Name: EPJ Quant.Technol. Journal Issue: 1 Vol. 13
• Country of Publication: United States
• Language: English