Related papers: Rhenium as a material platform for long-lived tran…
Surface dielectric loss of superconducting transmon qubit is believed as one of the dominant sources of decoherence. Reducing surface dielectric loss of superconducting qubit is known to be a great challenge for achieving high quality…
The lifetime of superconducting qubits is limited by dielectric loss, and a major source of dielectric loss is the native oxide present at the surface of the superconducting metal. Specifically, tantalum-based superconducting qubits have…
Superconducting qubits are considered as a promising platform for implementing a fault tolerant quantum computing. However, surface defects of superconductors and the substrate leading to qubit state decoherence and fluctuations in qubit…
We demonstrate enhanced relaxation and dephasing times of transmon qubits, up to ~ 60 \mu s by fabricating the interdigitated shunting capacitors using titanium nitride (TiN). Compared to lift-off aluminum deposited simultaneously with the…
The presence of amorphous oxide layers can significantly affect the coherent time of superconducting qubits due to their high dielectric loss. Typically, the surface oxides of superconductor films exhibit lossy and unstable behavior when…
We systematically investigate the influence of the fabrication process on dielectric loss in aluminum-on-silicon superconducting coplanar waveguide resonators with internal quality factors ($Q_i$) of about one million at the single-photon…
Atomically thin materials such as graphene are uniquely responsive to charge transfer from adjacent materials, making them ideal charge transport layers in phototransistor devices. Effective implementation of organic semiconductors as a…
Improving the performance of superconducting qubits and resonators generally results from a combination of materials and fabrication process improvements and design modifications that reduce device sensitivity to residual losses. One…
The use of $\alpha$-tantalum in superconducting circuits has enabled a considerable improvement of the coherence time of transmon qubits. The standard approach to grow $\alpha$-tantalum thin films on silicon involves heating the substrate,…
Bulk rhenium trioxide (ReO3) has an unusually high electrical conductivity and, being nanosized, has promising catalytic properties. However, the production of pure ReO3 thin films is challenging due to the difficulty to stabilize rhenium…
Tantalum-based transmon qubits are a promising platform for building large-scale quantum processors. So far, these qubits have been made from tantalum films grown exclusively in the alpha phase ({\alpha}-Ta). The beta phase of tantalum…
State-of-the-art superconducting qubits rely on a limited set of thin-film materials. Expanding their materials palette can improve performance, extend operating regimes, and introduce new functionalities, but conventional thin-film…
We assess independently the impact of high-temperature substrate annealing and metal deposition conditions on the coherence of transmon qubits in the standard 2D circuit-QED architecture. We restrict our study to devices made with aluminum…
Analytical formulas are presented for simplified but useful qubit geometries that predict surface dielectric loss when its thickness is much less than the metal thickness, the limiting case needed for real devices. These formulas can thus…
The spin- and energy-dependent interface reflectivity of a ferromagnetic (FM) film in contact with a nonmagnetic (NM) film is calculated using a first-principles transport method and incorporated into the superdiffusive spin transport model…
Superconductor qubits typically use aluminum-aluminum oxide tunnel junctions to provide the non-linear inductance. Junctions with semiconductor barriers make it possible to vary the superconductor material and explore beyond aluminum. We…
We study the energy relaxation times ($T_1$) of superconducting transmon qubits in 3D cavities as a function of dielectric participation ratios of material surfaces. This surface participation ratio, representing the fraction of electric…
Superconducting qubits have emerged as a potentially foundational platform technology for addressing complex computational problems deemed intractable with classical computing. Despite recent advances enabling multiqubit designs that…
Reducing materials and processing-induced decoherence is critical to the development of utility-scale quantum processors based on superconducting qubits. Here we report on the impact of two fluorine-based wet etches, which we use to treat…
Material losses in metals are a central bottleneck in plasmonics for many applications. Here we propose and theoretically demonstrate that metal losses can be successfully mitigated with dielectric particles on metallic films, giving rise…