Tunable Coupling Architectures with Capacitively Connecting Pads for Large-Scale Superconducting Multi-Qubit Processors

• URL: http://arxiv.org/abs/2306.05312v1
• Date: Thu, 8 Jun 2023 16:00:54 GMT
• Title: Tunable Coupling Architectures with Capacitively Connecting Pads for Large-Scale Superconducting Multi-Qubit Processors
• Authors: Gui-Han Liang, Xiao-Hui Song, Cheng-Lin Deng, Xu-Yang Gu, Yu Yan, Zheng-Yang Mei, Si-Lu Zhao, Yi-Zhou Bu, Yong-Xi Xiao, Yi-Han Yu, Ming-Chuan Wang, Tong Liu, Yun-Hao Shi, He Zhang, Xiang Li, Li Li, Jing-Zhe Wang, Ye Tian, Shi-Ping Zhao, Kai Xu, Heng Fan, Zhong-Cheng Xiang, and Dong-Ning Zheng
• Abstract summary: We have proposed and experimentally verified a tunable inter-qubit coupling scheme for large-scale integration of superconducting qubits. The key feature of the scheme is the insertion of connecting pads between qubit and tunable coupling element. The increased inter-qubit distance provides more wiring space for flip-chip process.
• Score: 25.606312606345444
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We have proposed and experimentally verified a tunable inter-qubit coupling scheme for large-scale integration of superconducting qubits. The key feature of the scheme is the insertion of connecting pads between qubit and tunable coupling element. In such a way, the distance between two qubits can be increased considerably to a few millimeters, leaving enough space for arranging control lines, readout resonators and other necessary structures. The increased inter-qubit distance provides more wiring space for flip-chip process and reduces crosstalk between qubits and from control lines to qubits. We use the term Tunable Coupler with Capacitively Connecting Pad (TCCP) to name the tunable coupling part that consists of a transmon coupler and capacitively connecting pads. With the different placement of connecting pads, different TCCP architectures can be realized. We have designed and fabricated a few multi-qubit devices in which TCCP is used for coupling. The measured results show that the performance of the qubits coupled by the TCCP, such as $T_1$ and $T_2$, was similar to that of the traditional transmon qubits without TCCP. Meanwhile, our TCCP also exhibited a wide tunable range of the effective coupling strength and a low residual ZZ interaction between the qubits by properly tuning the parameters on the design. Finally, we successfully implemented an adiabatic CZ gate with TCCP. Furthermore, by introducing TCCP, we also discuss the realization of the flip-chip process and tunable coupling qubits between different chips.

Related papers

• High-performance multiqubit system with double-transmon couplers: Toward scalable superconducting quantum computers [0.0]
  We numerically analyze a system of three fixed-frequency qubits coupled via two double-transmon couplers (DTCs) The DTC is a recently proposed tunable coupler, which consists of two fixed-frequency transmons coupled through a common loop with an additional Josephson junction. We find that the DTC can not only reduce undesired residual couplings sufficiently, as well as in isolated two-qubits systems.
  arXiv  Detail & Related papers  (2024-02-08T02:44:24Z)
• Modular Superconducting Qubit Architecture with a Multi-chip Tunable Coupler [0.0]
  We use a floating tunable coupler to mediate interactions between qubits on separate chips. We show that the zero-coupling condition between qubits on separate chips can be achieved in each design. We demonstrate two-qubit gate operations with fidelity at the same level as qubits with a tunable coupler on a single chip.
  arXiv  Detail & Related papers  (2023-08-18T02:00:33Z)
• The SpinBus Architecture: Scaling Spin Qubits with Electron Shuttling [42.60602838972598]
  We introduce the SpinBus architecture, which uses electron shuttling to connect qubits and features low operating frequencies and enhanced qubit coherence. Control using room temperature instruments can plausibly support at least 144 qubits, but much larger numbers are conceivable with cryogenic control circuits.
  arXiv  Detail & Related papers  (2023-06-28T16:24:11Z)
• Circuit Cutting with Non-Maximally Entangled States [59.11160990637615]
  Distributed quantum computing combines the computational power of multiple devices to overcome the limitations of individual devices. circuit cutting techniques enable the distribution of quantum computations through classical communication. Quantum teleportation allows the distribution of quantum computations without an exponential increase in shots. We propose a novel circuit cutting technique that leverages non-maximally entangled qubit pairs.
  arXiv  Detail & Related papers  (2023-06-21T08:03:34Z)
• Two qubits in one transmon -- QEC without ancilla hardware [68.8204255655161]
  We show that it is theoretically possible to use higher energy levels for storing and controlling two qubits within a superconducting transmon. The additional qubits could be used in algorithms which need many short-living qubits in error correction or by embedding effecitve higher connectivity in qubit networks.
  arXiv  Detail & Related papers  (2023-02-28T16:18:00Z)
• Long-distance transmon coupler with CZ gate fidelity above $99.8\%$ [37.50928453361462]
  We demonstrate a tunable qubit-qubit coupler based on a floating transmon device. We place qubits at least 2 mm apart from each other while maintaining over 50 MHz coupling between the coupler and the qubits.
  arXiv  Detail & Related papers  (2022-08-19T17:37:56Z)
• Controlled-Controlled-Phase Gates for Superconducting Qubits Mediated by a Shared Tunable Coupler [0.0]
  We investigate a system of three superconducting transmon-type qubits coupled via a single flux-tunable coupler. tuning the frequency of the coupler by adiabatic flux pulses enables us to control the conditional energy shifts between the qubits. Numerical simulations result in fidelities around 99 % and gate times below 300 ns.
  arXiv  Detail & Related papers  (2022-06-24T17:47:11Z)
• 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)
• Floating tunable coupler for scalable quantum computing architectures [0.0]
  We show that the polarity of the qubit-coupler couplings can be engineered to offset the otherwise constant qubit-qubit coupling. Such a floating tunable coupler provides flexibility in designing large-scale quantum processors.
  arXiv  Detail & Related papers  (2021-03-12T01:32:32Z)
• Universal non-adiabatic control of small-gap superconducting qubits [47.187609203210705]
  We introduce a superconducting composite qubit formed from two capacitively coupled transmon qubits. We control this low-frequency CQB using solely baseband pulses, non-adiabatic transitions, and coherent Landau-Zener interference. This work demonstrates that universal non-adiabatic control of low-frequency qubits is feasible using solely baseband pulses.
  arXiv  Detail & Related papers  (2020-03-29T22:48:34Z)

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.