Discovery of Niobium Hydride Precipitates in Superconducting Qubits
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912537978601472 |
|---|---|
| author | Sung, Zuhawn Bafia, Daniel Cano, Arely Murthy, Akshay Lee, Jaeyel Reagor, Matthew J Rubio-Zuazo, Juan Grassellino, Anna Romanenko, Alexander |
| author_facet | Sung, Zuhawn Bafia, Daniel Cano, Arely Murthy, Akshay Lee, Jaeyel Reagor, Matthew J Rubio-Zuazo, Juan Grassellino, Anna Romanenko, Alexander |
| contents | We report the evidence of the formation of niobium hydride phase within niobium films on silicon substrates in superconducting qubits fabricated at Rigetti Computing. For this study, we combined complementary techniques, including room-temperature and cryogenic atomic force microscopy (AFM), synchrotron Xray diffraction, and time of flight secondary ion mass spectroscopy (ToF-SIMS), to directly reveal the existence of niobium hydride precipitates in the Rigetti chip area. Upon cryogenic cooling, we observed variation in the size and morphology of the hydrides, ranging from small (5 nm) irregular shapes to large (~10-100 nm) domain within the Nb grains, fully converted to niobium hydrides. Since niobium hydrides are non-superconducting and can easily change in size and location upon different cooldowns to cryogenic temperature, our finding highlights a new and previously unknown source of decoherence in superconducting qubits. This contributes to both quasiparticle and two level system (TLS) losses, offering a potential explanation for changes in qubit performance upon cooldowns. Finally, by leveraging the RF performance of a 3D bulk Nb resonator, we can quantify RF dissipation on a superconducting qubit, caused by hydrogen concentration variation, and are able to propose a practical engineering pathway to mitigate the formation of the Nb hydrides for superconducting qubit applications. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2508_10889 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Discovery of Niobium Hydride Precipitates in Superconducting Qubits Sung, Zuhawn Bafia, Daniel Cano, Arely Murthy, Akshay Lee, Jaeyel Reagor, Matthew J Rubio-Zuazo, Juan Grassellino, Anna Romanenko, Alexander Superconductivity We report the evidence of the formation of niobium hydride phase within niobium films on silicon substrates in superconducting qubits fabricated at Rigetti Computing. For this study, we combined complementary techniques, including room-temperature and cryogenic atomic force microscopy (AFM), synchrotron Xray diffraction, and time of flight secondary ion mass spectroscopy (ToF-SIMS), to directly reveal the existence of niobium hydride precipitates in the Rigetti chip area. Upon cryogenic cooling, we observed variation in the size and morphology of the hydrides, ranging from small (5 nm) irregular shapes to large (~10-100 nm) domain within the Nb grains, fully converted to niobium hydrides. Since niobium hydrides are non-superconducting and can easily change in size and location upon different cooldowns to cryogenic temperature, our finding highlights a new and previously unknown source of decoherence in superconducting qubits. This contributes to both quasiparticle and two level system (TLS) losses, offering a potential explanation for changes in qubit performance upon cooldowns. Finally, by leveraging the RF performance of a 3D bulk Nb resonator, we can quantify RF dissipation on a superconducting qubit, caused by hydrogen concentration variation, and are able to propose a practical engineering pathway to mitigate the formation of the Nb hydrides for superconducting qubit applications. |
| title | Discovery of Niobium Hydride Precipitates in Superconducting Qubits |
| topic | Superconductivity |
| url | https://arxiv.org/abs/2508.10889 |