Magnetic bound states embedded in tantalum superconducting thin films
arXiv:2412.15903 · doi:10.1063/5.0251996
Abstract
In the fabrication of superconducting devices, both in situ and ex situ processes are utilized, making the removal of unwanted oxide layers and impurities under vacuum conditions crucial. Oxygen descumming and argon milling are standard in situ cleaning methods employed for device preparation. We investigated the impact of these techniques on tantalum superconducting thin films using scanning tunneling microscopy at millikelvin temperatures. We demonstrate that these cleaning methods inadvertently introduce magnetic bound states within the superconducting gap of tantalum, likely by oxygen impurities. These bound states can be detrimental to superconducting qubit devices, as they add to dephasing and energy relaxation.
References in corpus (14)
- Circuit Quantum Electrodynamics
- New material platform for superconducting transmon qubits with coherence times exceeding 0.3 milliseconds
- Tunneling processes into localized subgap states in superconductors
- Tuning the coupling of an individual magnetic impurity to a superconductor: quantum phase transition and transport
- Local Electronic Structure of a Single Magnetic Impurity in a Superconductor
- Disentangling Losses in Tantalum Superconducting Circuits
- Magnetic anisotropy effects on quantum impurities in superconducting host
- Chemical profiles of the oxides on tantalum in state of the art superconducting circuits
- A compact ultrahigh vacuum scanning tunneling microscope with dilution refrigeration
- Effect of Ion Bombardment on the Chemical Properties of Crystalline Tantalum Pentoxide Films
- Microscopic charging and in-gap states in superconducting granular aluminum
- Oxygen vacancy-driven orbital multichannel Kondo effect in Dirac nodal line metals IrO2 and RuO2
- Zeeman effects on Yu-Shiba-Rusinov states
- Quantum spin driven Yu-Shiba-Rusinov multiplets and fermion-parity-preserving phase transition in KC