Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch
- URL: http://arxiv.org/abs/2408.02863v1
- Date: Mon, 5 Aug 2024 23:25:46 GMT
- Title: Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch
- Authors: Cameron J. Kopas, Dominic P. Goronzy, Thang Pham, Carlos G. Torres Castanedo, Matthew Cheng, Rory Cochrane, Patrick Nast, Ella Lachman, Nikolay Z. Zhelev, Andre Vallieres, Akshay A. Murthy, Jin-su Oh, Lin Zhou, Matthew J. Kramer, Hilal Cansizoglu, Michael J. Bedzyk, Vinayak P. Dravid, Alexander Romanenko, Anna Grassellino, Josh Y. Mutus, Mark C. Hersam, Kameshwar Yadavalli,
- Abstract summary: Performance of superconducting qubits is often limited by dissipation and two-level systems (TLS) losses.
Here, we explore a novel wet chemical surface treatment at the Josephson junction-substrate and the substrate-air interface.
- Score: 29.705263765768372
- License: http://creativecommons.org/licenses/by-nc-nd/4.0/
- Abstract: The performance of superconducting qubits is often limited by dissipation and two-level systems (TLS) losses. The dominant sources of these losses are believed to originate from amorphous materials and defects at interfaces and surfaces, likely as a result of fabrication processes or ambient exposure. Here, we explore a novel wet chemical surface treatment at the Josephson junction-substrate and the substrate-air interfaces by replacing a buffered oxide etch (BOE) cleaning process with one that uses hydrofluoric acid followed by aqueous ammonium fluoride. We show that the ammonium fluoride etch process results in a statistically significant improvement in median $\text{T}_1$ by $\sim22\%$ ($p=0.002$), and a reduction in the number of strongly-coupled TLS in the tunable frequency range. Microwave resonator measurements on samples treated with the ammonium fluoride etch prior to niobium deposition also show $\sim33\%$ lower TLS-induced loss tangent compared to the BOE treated samples. As the chemical treatment primarily modifies the Josephson junction-substrate interface and substrate-air interface, we perform targeted chemical and structural characterizations to examine materials' differences at these interfaces and identify multiple microscopic changes that could contribute to decreased TLS.
Related papers
- Effect of Etching Methods on Dielectric Losses in Transmons [0.0]
Transmons produced by two different methods of aluminum etching: wet etching in a solution of weak acids and dry etching using a chlorine-based plasma are experimentally studied.
The relaxation and coherence times for dry-etched qubits are more than twice as long as those for wet-etched ones.
arXiv Detail & Related papers (2024-09-24T13:52:12Z) - Single photon emitters in monolayer semiconductors coupled to transition metal dichalcogenide nanoantennas on silica and gold substrates [49.87501877273686]
Transition metal dichalcogenide (TMD) single photon emitters offer numerous advantages to quantum information applications.
Traditional materials used for the fabrication of nanoresonators, such as silicon or gallium phosphide (GaP), often require a high refractive index substrate.
Here, we use nanoantennas (NAs) fabricated from multilayer TMDs, which allow complete flexibility with the choice of substrate.
arXiv Detail & Related papers (2024-08-02T07:44:29Z) - Characterization of process-related interfacial dielectric loss in
aluminum-on-silicon by resonator microwave measurements, materials analysis,
and imaging [0.0]
We investigate the influence of the fabrication process on dielectric loss in aluminum-on-silicon superconducting coplanar waveguide resonators.
These devices are essential components in superconducting quantum processors.
We identify the relative importance of reducing loss at the substrate-metal and the substrate-air interfaces.
arXiv Detail & Related papers (2024-03-01T18:16:28Z) - Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium
Surface Encapsulation [25.617374322523048]
We present a novel transmon qubit fabrication technique that yields systematic improvements in relaxation times.
We fabricate devices using an encapsulation strategy that involves passivating the surface of niobium.
arXiv Detail & Related papers (2023-04-26T02:59:28Z) - Developing a Chemical and Structural Understanding of the Surface Oxide
in a Niobium Superconducting Qubit [46.6940373636939]
We conduct a detailed assessment of the surface oxide that forms in ambient conditions for transmon test devices patterned from a niobium film.
In terms of structural analysis, we find that the Nb$ 1-2$O$_5$ region is semicrystalline in nature.
We observe that amorphous regions are more likely to contain oxygen vacancies and exhibit weaker bonds between the niobium and oxygen atoms.
arXiv Detail & Related papers (2022-03-16T16:00:57Z) - Ternary Metal Oxide Substrates for Superconducting Circuits [65.60958948226929]
Substrate material imperfections and surface losses are one of the major factors limiting superconducting quantum circuitry from reaching the scale and complexity required to build a practicable quantum computer.
Here, we examine two ternary metal oxide materials, spinel (MgAl2O4) and lanthanum aluminate (LaAlO3), with a focus on surface and interface characterization and preparation.
arXiv Detail & Related papers (2022-01-17T06:10:15Z) - TOF-SIMS Analysis of Decoherence Sources in Nb Superconducting
Resonators [48.7576911714538]
Superconducting qubits have emerged as a potentially foundational platform technology.
Material quality and interfacial structures continue to curb device performance.
Two-level system defects in the thin film and adjacent regions introduce noise and dissipate electromagnetic energy.
arXiv Detail & Related papers (2021-08-30T22:22:47Z) - Effects of surface treatments on flux tunable transmon qubits [2.9925148326664854]
Adsorbates on surfaces, impurities at interfaces and material defects have been identified as sources of noise and dissipation in quantum devices.
Here, we use an ultra-high vacuum package to study the impact of vacuum loading, UV-light exposure and ion irradiation treatments on coherence and slow parameter fluctuations of flux superconducting transmon qubits.
arXiv Detail & Related papers (2021-03-14T16:36:24Z) - Quantum Sensors for Microscopic Tunneling Systems [58.720142291102135]
tunneling Two-Level-Systems (TLS) are important for micro-fabricated quantum devices such as superconducting qubits.
We present a method to characterize individual TLS in virtually arbitrary materials deposited as thin-films.
Our approach opens avenues for quantum material spectroscopy to investigate the structure of tunneling defects.
arXiv Detail & Related papers (2020-11-29T09:57:50Z) - Microscopic Relaxation Channels in Materials for Superconducting Qubits [76.84500123816078]
We show correlations between $T_$ and grain size, enhanced oxygen diffusion along grain boundaries, and concentration of suboxides near the surface.
Physical mechanisms connect these microscopic properties to residual surface resistance and $T_$ through losses arising from the grain boundaries and from defects in the suboxides.
This comprehensive approach to understanding qubit decoherence charts a pathway for materials-driven improvements of superconducting qubit performance.
arXiv Detail & Related papers (2020-04-06T18:01:15Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.