A5093583468- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Ferroelectric and Piezoelectric Materials
- Magnetic properties of thin films
- 2D Materials and Applications
- Quantum, superfluid, helium dynamics
- Surface and Thin Film Phenomena
- Atomic and Subatomic Physics Research
- Graphene research and applications
- Multiferroics and related materials
Brookhaven National Laboratory
2023-2025
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
2025
The lifetime of superconducting qubits is limited by dielectric loss, and a major source loss the native oxide present at surface metal. Specifically, tantalum-based have been demonstrated with record lifetimes, but presence two-level systems in tantalum oxide. Here, we demonstrate strategy for avoiding formation encapsulating noble metals that do not form By depositing few nanometers Au or AuPd alloy before breaking vacuum, completely suppress formation. Microwave measurements resonators...
Abstract Despite constituting a smaller fraction of the qubit's electromagnetic mode, surfaces and interfaces can exert significant influence as sources high‐loss tangents, which brings forward need to reveal properties these extended defects identify routes their control. Here, we examine structure composition metal‐substrate interfacial layer that exists in Ta/sapphire‐based superconducting films. Synchrotron‐based X‐ray reflectivity measurements Ta films, commonly used qubits, an...
Abstract Scaling up superconducting quantum circuits based on transmon qubits necessitates substantial enhancements in qubit coherence time. Over recent years, tantalum (Ta) has emerged as a promising candidate for qubits, surpassing conventional counterparts terms of However, amorphous surface Ta oxide layer may introduce dielectric loss, ultimately placing limit the In this study, novel approach suppressing formation using an ultrathin magnesium (Mg) capping is presented. Synchrotron‐based...
Two-dimensional van der Waals magnets hosting topological magnetic textures, such as skyrmions, show promise for spintronics and quantum computing. Electrical control of these spin textures is crucial enhancing operational performance functionality. Here, using electron microscopy combined with in situ electric biasing, we that the skyrmion helicity insulating Cr2Ge2Te6 can be controlled by direction external field applied during cooling process. The field-tuned remains stable at low...
Recent advances in superconducting qubit technology have led to significant progress quantum computing, but the challenge of achieving a long coherence time remains. Despite excellent lifetime performance that tantalum (Ta) based qubits demonstrated date, majority systems, including Ta-based qubits, are generally believed uncontrolled surface oxidation as primary source two-level system loss two-dimensional transmon qubits. Therefore, atomic-scale insight into process is needed make toward...
Abstract Lead-free SrBi 2 Ta O 9 (SBT) has been a promising ferroelectric material for various applications such as electronics and data storage due to its outstanding properties including high fatigue endurance low leakage current. However, the atomic-scale domain structure switching dynamics of SBT remain elusive. This study reveals that spontaneous polarization arises from canted bismuth-cation displacements, forming 90° Ising-type 180° walls. Interestingly, topological pairs vortex...
The lifetime of superconducting qubits is limited by dielectric loss, and a major source loss the native oxide present at surface metal. Specifically, tantalum-based have been demonstrated with record lifetimes, but presence two-level systems (TLSs) in tantalum oxide. Here, we demonstrate strategy for avoiding formation encapsulating noble metals that do not form By depositing few nanometers Au or AuPd alloy before breaking vacuum, completely suppress formation. Microwave measurements...
Superconducting resonators play a pivotal role in various quantum technology applications, such as computing and high-frequency communication systems. The performance of these is closely tied to the properties superconducting films used their fabrication. In this study, we investigated impact wet dry etching on tantalum (Ta) leveraging advanced scanning transmission electron microscopy-based characterization methods examined morphological, chemical, strain changes caused by processes....