Contacting Josephson Junctions via Airbridges in Superconducting Circuits

• URL: http://arxiv.org/abs/2606.06951v1
• Date: Fri, 05 Jun 2026 06:24:47 GMT
• Title: Contacting Josephson Junctions via Airbridges in Superconducting Circuits
• Abstract summary: We introduce textitall electrical interconnects with airbridges of varying size fabricated in a single step.<n>The airbridges show a high yield and mechanical stability over a wide range of sizes from $0.5,mathrmm$ to $4,mathrmm$ in width and from $5,mathrmm$ to $40,mathrmm$ in length, and show low loss when integrated in coplanar waveguide resonators and transmon qubits.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Superconducting circuit devices require electrical interconnects between different circuit elements on the chip, for which conventional device architectures use a combination of two structural elements: \textit{airbridges} to connect non-adjacent elements in the base layer, and \textit{bandages} to connect the electrodes forming the Josephson junctions to the base layer. Bandages introduce unwanted parasitic material interfaces and increase the manufacturing complexity. Here, we overcome the limitations imposed by \emph{bandages} by establishing \textit{all} electrical interconnects with airbridges of varying size fabricated in a single step. The airbridges show a high yield and mechanical stability over a wide range of sizes from $0.5\,μ\mathrm{m}$ to $4\,μ\mathrm{m}$ in width and from $5\,μ\mathrm{m}$ to $40\,μ\mathrm{m}$ in length, and show low loss when integrated in coplanar waveguide resonators and transmon qubits. Measured relaxation times up to more than $250\,μ\mathrm{s}$ in standard transmon geometries show that the process achieves high coherence while substantially easing and accelerating device fabrication.

Related papers

• Flip-chip integrated superconducting qubits using electroplated bump bonds [1.5030949006750438]
  We develop a three-dimensional transmon architecture using electroplated indium.<n>We evaluate electroplated indium interconnects for superconducting quantum circuits.
  arXiv  Detail & Related papers  (2026-08-07T15:01:24Z)
• Machine Learning-Based Reconstruction for Resistive Silicon Sensors [53.365453214937496]
  We study machine-learning-based reconstruction and compression for resistive silicon sensors.<n>We use full-waveform information from correlated pads to regularise the reconstruction and extract spatial information.<n>We first introduce recurrent neural network models based on LSTM layers, which provide a proof-of-concept implementation for full-waveform reconstruction.
  arXiv  Detail & Related papers  (2026-07-13T14:03:26Z)
• Flux-tunable transmon incorporating a van der Waals superconductor via an Al/AlO$_x$/4Hb-TaS$_2$ Josephson junction [0.0]
  van der Waals (vdW) superconductors into Josephson elements extends circuit-QED beyond conventional Al/AlO$_x$/Al tunnel junctions.<n>In this work, we realize a flux-tunable transmon whose nonlinear inductive element is an Al/AlO$_x$/4Hb-TaS$$$ Josephson junction.
  arXiv  Detail & Related papers  (2026-01-27T13:12:34Z)
• Hyperinductance based on stacked Josephson junctions [0.0]
  Superinductances are key enablers for emerging quantum circuit architectures.<n>We present two fabrication techniques for realizing superinductances based on vertically stacked Josephson junctions.<n>Our results establish junction stacking as a scalable, robust, and flexible platform for next-generation quantum circuits.
  arXiv  Detail & Related papers  (2025-05-05T16:20:14Z)
• Improved Coherence in Optically-Defined Niobium Trilayer Junction Qubits [45.786749852292246]
  Niobium offers the benefit of increased operating temperatures and frequencies for superconducting devices. We revisit niobium trilayer junctions and fabricate all-niobium transmons using only optical lithography. We characterize devices in the microwave domain, measuring coherence times up to $62mu$s and an average qubit quality factor above $105$.
  arXiv  Detail & Related papers  (2023-06-09T13:26:13Z)
• Improving Josephson junction reproducibility for superconducting quantum circuits: junction area fluctuation [0.0]
  Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits. critical current $I_c$ variation of the Josephson junction, as the most important electrical parameter, needs to be minimized. We optimized Josephson junctions fabrication process and demonstrate resistance variation of $9.8-4.4%$ and $4.8-2.3%$ across $22times22$ $mm2$ and $5times10$ $mm2$ chip areas.
  arXiv  Detail & Related papers  (2022-10-27T10:00:24Z)
• Erasure qubits: Overcoming the $T_1$ limit in superconducting circuits [105.54048699217668]
  amplitude damping time, $T_phi$, has long stood as the major factor limiting quantum fidelity in superconducting circuits. We propose a scheme for overcoming the conventional $T_phi$ limit on fidelity by designing qubits in a way that amplitude damping errors can be detected and converted into erasure errors.
  arXiv  Detail & Related papers  (2022-08-10T17:39:21Z)
• Topological Josephson parametric amplifier array: A proposal for directional, broadband, and low-noise amplification [39.58317527488534]
  Low-noise microwave amplifiers are crucial for detecting weak signals in fields such as quantum technology and radio astronomy. We show that compact devices with few sites can achieve exceptional performance, with gains exceeding 20 dB over a bandwidth ranging from hundreds of MHz to GHz. The device also operates near the quantum noise limit and provides topological protection against up to 15% fabrication disorder.
  arXiv  Detail & Related papers  (2022-07-27T18:07:20Z)
• Aluminum air bridges for superconducting quantum devices realized using a single step electron-beam lithography process [0.0]
  In superconducting quantum devices, air bridges enable increased circuit complexity and density. We implement aluminum air bridges using a simple process based on single-step electron-beam gradient exposure. The resulting bridges have sizes ranging from $20mu m$ to $100mu m$, with a yield exceeding $99%$ for lengths up to $36mu m$.
  arXiv  Detail & Related papers  (2022-06-19T21:33:28Z)
• High fidelity two-qubit gates on fluxoniums using a tunable coupler [47.187609203210705]
  Superconducting fluxonium qubits provide a promising alternative to transmons on the path toward large-scale quantum computing. A major challenge for multi-qubit fluxonium devices is the experimental demonstration of a scalable crosstalk-free multi-qubit architecture. Here, we present a two-qubit fluxonium-based quantum processor with a tunable coupler element.
  arXiv  Detail & Related papers  (2022-03-30T13:44:52Z)
• High Coherence in a Tileable 3D Integrated Superconducting Circuit Architecture [0.0]
  We report high qubit coherence as well as low crosstalk and single-qubit gate errors in a superconducting circuit architecture that promises to be tileable to 2D lattices of qubits. The architecture integrates an inductivelyed cavity enclosure into a design featuring non-galvanic out-of-plane control wiring and qubits and resonators fabricated on opposing sides of a substrate.
  arXiv  Detail & Related papers  (2021-07-23T11:08:07Z)
• In-situ bandaged Josephson junctions for superconducting quantum processors [101.18253437732933]
  Shadow evaporation is commonly used to micro-fabricate the key element of superconducting qubits - the Josephson junction. Here, we present an improved shadow evaporation technique allowing one to fabricate sub-micrometer-sized Josephson junctions together with bandage layers in a single lithography step.
  arXiv  Detail & Related papers  (2021-01-05T11:08:09Z)
• Coherent superconducting qubits from a subtractive junction fabrication process [48.7576911714538]
  Josephson tunnel junctions are the centerpiece of almost any superconducting electronic circuit, including qubits. In recent years, sub-micron scale overlap junctions have started to attract attention. This work paves the way towards a more standardized process flow with advanced materials and growth processes, and constitutes an important step for large scale fabrication of superconducting quantum circuits.
  arXiv  Detail & Related papers  (2020-06-30T14:52:14Z)

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.