Ultracoherent superconducting cavity-based multiqudit platform with error-resilient control

• URL: http://arxiv.org/abs/2506.03286v2
• Date: Thu, 07 Aug 2025 20:38:34 GMT
• Title: Ultracoherent superconducting cavity-based multiqudit platform with error-resilient control
• Authors: Taeyoon Kim, Tanay Roy, Xinyuan You, Andy C. Y. Li, Henry Lamm, Oleg Pronitchev, Mustafa Bal, Sabrina Garattoni, Francesco Crisa, Daniel Bafia, Doga Kurkcuoglu, Roman Pilipenko, Paul Heidler, Nicholas Bornman, David van Zanten, Silvia Zorzetti, Roni Harnik, Akshay Murthy, Andrei Lunin, Sergey Belomestnykh, Shaojiang Zhu, Changqing Wang, Andre Vallieres, Ziwen Huang, Jens Koch, Anna Grassellino, Srivatsan Chakram, Alexander Romanenko, Yao Lu,
• Abstract summary: Superconducting radio-frequency (SRF) cavities offer a promising platform for quantum computing.<n>We report a multimode quantum system based on a 2-cell elliptical shaped SRF cavity, comprising two cavity modes weakly coupled to an ancillary transmon circuit.<n>We achieve single-photon lifetimes of 20.6 ms and 15.6 ms for the two modes, and a pure dephasing time exceeding 40 ms.
• Score: 27.481637966670217
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Superconducting radio-frequency (SRF) cavities offer a promising platform for quantum computing due to their long coherence times, yet integrating nonlinear elements like transmons for control often introduces additional loss. We report a multimode quantum system based on a 2-cell elliptical shaped SRF cavity, comprising two cavity modes weakly coupled to an ancillary transmon circuit, designed to preserve coherence while enabling efficient control of the cavity modes. We mitigate the detrimental effects of the transmon decoherence through careful design optimization that reduces transmon-cavity couplings and participation in the dielectric substrate and lossy interfaces, to achieve single-photon lifetimes of 20.6 ms and 15.6 ms for the two modes, and a pure dephasing time exceeding 40 ms. This marks an order-of-magnitude improvement over prior 3D multimode memories. Leveraging sideband interactions and novel error-resilient protocols, including measurement-based correction and post-selection, we achieve high-fidelity control over quantum states. This enables the preparation of Fock states up to $N = 20$ with fidelities exceeding 95%, the highest reported to date to the authors' knowledge, as well as two-mode entanglement with an estimated coherence-limited fidelities of 99.9% after post-selection. These results establish our platform as a robust foundation for quantum information processing, allowing for future extensions to high-dimensional qudit encodings.

Related papers

• Flux-Activated Resonant Control of a Bosonic Quantum Memory [63.35373457838474]
  Bosonic circuit quantum electrodynamics (cQED) coherently control long-lived superconducting cavities.<n>We integrate an on-chip flux-control architecture with a long-lived bosonic memory housed in a 3D superconducting cavity.<n>We realize efficient arbitrary rotations between any pair of Fock levels in the memory.
  arXiv  Detail & Related papers  (2026-02-20T10:22:53Z)
• Hardware-Efficient Bosonic Module for Entangling Superconducting Quantum Processors via Optical Networks [5.181101976838568]
  Microwave-to-optical (M2O) transducers pose challenges due to frequency mismatches and qubit decoherence.<n>We propose a modular architecture using SNAIL-based parametric coupling to interface Brillouin M2O transducers with long-lived 3D cavities.<n>Our cavity-based approach outperforms transmon schemes, providing a practical pathway for distributed superconducting quantum computing.
  arXiv  Detail & Related papers  (2025-11-13T15:27:57Z)
• High-fidelity two-qubit gates with transmon qubits using bipolar flux pulses and tunable couplers [25.989599596628693]
  Scheme based on superconducting transmon qubits and control pulse delivery protocol.<n>We demonstrate a high-fidelity two-qubit gate with a performance of $99.5%$.<n>We confirm the scalability potential of the proposed scheme on a high-fidelity 4-qubit quantum processor.
  arXiv  Detail & Related papers  (2025-09-05T09:43:29Z)
• Tunable Superconducting Quantum Interference Device Coupler for Fluxonium Qubits [0.8691965235932587]
  Tunable couplers enable high-fidelity two-qubit gates leveraging high on/off coupling ratios and reduced crosstalk within a single design.<n>We present two schemes to implement two-qubit gates, predicting a $sqrtitextSWAP$-like gate with $99.9%$ open-system fidelity in less than 6 nanoseconds.
  arXiv  Detail & Related papers  (2025-08-23T05:42:59Z)
• Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device [58.154405222706146]
  tuning of qubit-coupler coupling strengths in a superconducting circuit with two transmon qubits coupled via a tunable coupler enables high-fidelity single- and two-qubit gates.<n>We achieve a 40h-averaged CZ gate fidelity of 99.93%, simultaneous single-qubit gate fidelities of 99.98%, and readout fidelities over 99.94% in a single device.
  arXiv  Detail & Related papers  (2025-08-22T14:49:47Z)
• Tunable Hybrid-Mode Coupler Enabling Strong Interactions between Transmons at Centimeter-Scale Distance [18.74264945106587]
  We introduce a hybrid-mode coupler exploiting resonator-transmon hybridization to simultaneously engineer the two lowest-frequency mode.<n>For a 1-cm coupler, our framework predicts flux-tunable $XX$ and $ZZ$ coupling strengths reaching 23 MHz and 100 MHz.<n>This work provides an efficient pathway to mitigate the inherent connectivity constraints imposed by short-range interactions.
  arXiv  Detail & Related papers  (2025-06-17T02:45:16Z)
• High-contrast interaction between remote superconducting qubits mediated by multimode cable coupling [1.5728609542259502]
  We show that a multimode coaxial cable can mediate high-contrast interaction between spatially separated qubits.<n>We can implement high-fidelity controlled-Z and ZZ-free iSWAP gates by simply modulating qubit frequencies.
  arXiv  Detail & Related papers  (2025-05-13T14:23:04Z)
• Fast Sideband Control of a Weakly Coupled Multimode Bosonic Memory [8.767643277178196]
  Circuit quantum electrodynamics with superconducting cavities and nonlinear circuits like transmons offers a promising platform for hardware-efficient quantum information processing.<n>We address critical challenges in realizing this architecture by weakening the dispersive coupling.<n>We demonstrate fast, high-fidelity multimode control by dynamically amplifying gate speeds through transmon-mediated sideband interactions.
  arXiv  Detail & Related papers  (2025-03-13T17:59:07Z)
• Joint Transmit and Pinching Beamforming for Pinching Antenna Systems (PASS): Optimization-Based or Learning-Based? [89.05848771674773]
  A novel antenna system ()-enabled downlink multi-user multiple-input single-output (MISO) framework is proposed.<n>It consists of multiple waveguides, which equip numerous low-cost antennas, named (PAs)<n>The positions of PAs can be reconfigured to both spanning large-scale path and space.
  arXiv  Detail & Related papers  (2025-02-12T18:54:10Z)
• Long-Range $ZZ$ Interaction via Resonator-Induced Phase in Superconducting Qubits [17.30641318218974]
  We propose a novel multimode coupling scheme using three resonators driven by two microwaves, based on the resonator-induced phase gate, to extend the $ZZ$ interaction distance between qubits. We demonstrate a CZ gate fidelity exceeding 99.9% within 160 ns at free spectral range (FSR) of 1.4 GHz, and by optimizing driving pulses, we further reduce the residual photon to nearly $10-3$ within 100 ns at FSR of 0.2 GHz.
  arXiv  Detail & Related papers  (2024-08-29T15:24:08Z)
• Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits [84.60542868688235]
  leakage out of the computational subspace arising from the multi-level structure of qubit implementations. We present a resource-efficient universal leakage reduction unit for superconducting qubits using parametric flux modulation. We demonstrate that using the leakage reduction unit in repeated weight-two stabilizer measurements reduces the total number of detected errors in a scalable fashion.
  arXiv  Detail & Related papers  (2023-09-13T16:21:32Z)
• Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory [47.00474212574662]
  A superconducting qubit is coupled to a large-bandwidth readout resonator. We show a beyond-state-of-the-art two-state-readout error of only 0.25,%$ in 100 ns integration time. The presented results are expected to further boost the performance of new and existing algorithms and protocols.
  arXiv  Detail & Related papers  (2023-07-15T10:30:10Z)
• 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)
• Path-encoded high-dimensional quantum communication over a 2 km multicore fiber [50.591267188664666]
  We demonstrate the reliable transmission over a 2 km long multicore fiber of path-encoded high-dimensional quantum states. A stable interferometric detection is guaranteed, allowing for low error rates and the generation of 6.3 Mbit/s of secret key rate.
  arXiv  Detail & Related papers  (2021-03-10T11:02:45Z)
• 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.