Gate-Based Microwave Quantum Repeater Via Grid-State Encoding

• URL: http://arxiv.org/abs/2512.19896v1
• Date: Mon, 22 Dec 2025 21:50:48 GMT
• Title: Gate-Based Microwave Quantum Repeater Via Grid-State Encoding
• Authors: Hany Khalifa, Matti Silveri,
• Abstract summary: We propose a second-generation gate-based microwave quantum repeater with encoded bosonic grid states.<n>The device can be implemented using currently available superconducting microwave technology.<n>It is suited for secure chip-to-chip communication and distributed quantum computing.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: In autonomous quantum error correction the lifetime of a logical bosonic qubit can be extended beyond its physical constituents without feedback measurements. Leveraging autonomous error correction, we propose a second-generation gate-based microwave quantum repeater (GBMQR) with encoded bosonic grid states. Each repeater station comprises a transmon and two bosonic resonators: one resonator serving as a stationary quantum memory utilizing autonomous error correction, and the other as an information bus for entanglement generation. Entanglement is generated sequentially through the successful absorption of a microwave photon wavepacket. This method enables deterministic entanglement generation, in contrast to a probabilistic mixing of two heralding signals on a balanced beamsplitter. Furthermore, our GBMQR employs an all-bosonic entanglement swapping Bell-state measurement. This is implemented via a bosonic controlled-Z gate and two separate X-basis projective homodyne measurements on the stationary stored codewords. Our approach circumvents mode-mismatch losses associated with routing and interfering of heralding modes on a beamsplitter, and confines losses to those arising from stationary storage. We evaluate the performance of the proposed quantum repeater by calculating its secret key rate under realistic lab environments. Moreover, we explicitly demonstrate that at stationary damping rate of $κ^{-1}_{\text{damp}}=$~\SI{40}{\milli\second}, GBMQR can achieve entanglement generation and swapping success probabilities approx.~$0.75$, and $0.58$ respectively, surpassing the hallmark success probability of $1/2$ set by ideal linear beamsplitter-based Bell-state measurements. The proposed device can be implemented using currently available superconducting microwave technology and is suited for secure chip-to-chip communication and distributed quantum computing.

Related papers

• Fault-tolerant modular quantum computing with surface codes using single-shot emission-based hardware [1.0138727338368827]
  Two main types of entanglement distribution protocols exist, emission-based and scattering-based.<n>We introduce protocols that completely eliminate the need for memory-based two-qubit gates.<n>Results show the feasibility of emission-based architectures for scalable fault-tolerant operation.
  arXiv  Detail & Related papers  (2026-01-12T06:23:13Z)
• Robust quantum communication through lossy microwave links [0.0]
  Entanglement fidelity is typically limited by photon loss in the links that connect superconducting qubits together.<n>We propose and realize a new scheme for heralded entanglement generation that almost entirely circumvents this limit.<n>Our work informs the design of future superconducting quantum networks.
  arXiv  Detail & Related papers  (2025-09-23T02:11:06Z)
• Programmable Microwave Cluster States via Josephson Metamaterials [0.0]
  Cluster states are a fundamental resource for continuous-variable quantum computing.<n>We demonstrate on-demand generation of multimode entangled microwave cluster states.<n>This platform opens new avenues for scalable measurement-based quantum information processing.
  arXiv  Detail & Related papers  (2025-07-30T16:37:37Z)
• Resonant two-qubit gates for fermionic simulations with spin qubits [0.0]
  We show a method to implement the fSim gate set in spin qubits using a single pulse combining baseband and resonant exchange drives.<n>This approach minimizes gate duration and drive amplitude, mitigating decoherence and crosstalk.<n>Our results establish a practical route toward a versatile and efficient two-qubit gate set for spin-based quantum processors.
  arXiv  Detail & Related papers  (2025-07-18T09:52:12Z)
• Crosstalk-Resilient Quantum MIMO for Scalable Quantum Communications [40.44880302154388]
  Crosstalk arises when physically coupled quantum modes interfere, degrading signal fidelity.<n>We propose a mitigation strategy based on encoding discrete-variable quantum information into continuous-variable modes.<n>We prove the existence of a gauge-fixing decoder enabling recovery of the logical information.
  arXiv  Detail & Related papers  (2025-06-26T18:40:26Z)
• Bosonic quantum error correction with microwave cavities for quantum repeaters [0.0]
  We provide a theoretical analysis of the secret key rates for a quantum repeater system incorporating bosonic error correction and memory components.<n>We discuss a physical implementation of such a quantum repeater comprising a microwave cavity and a superconducting transmon.
  arXiv  Detail & Related papers  (2025-03-27T14:50:57Z)
• Experimental Virtual Quantum Broadcasting [1.2050877805909537]
  We report the experimental implementation of a quantum circuit based on the linear combination of unitaries, integrated with a post-processing protocol.<n>We show how the universal antisymmetrizer can be utilized to mitigate imperfections in the cloner, enabling near-ideal fidelity.
  arXiv  Detail & Related papers  (2025-01-20T10:33:35Z)
• Controlled-squeeze gate in superconducting quantum circuits [39.58317527488534]
  We present a method to prepare non-classical states of the electromagnetic field in a microwave resonator.<n>It is based on a controlled gate that applies a squeezing operation on a SQUID-terminated resonator conditioned on the state of a dispersively coupled qubit.<n>We explore the use of this tool to map an arbitrary qubit state into a superposition of squeezed states.
  arXiv  Detail & Related papers  (2024-08-15T20:14:58Z)
• A high on-off ratio beamsplitter interaction for gates on bosonically encoded qubits [40.96261204117952]
  A qubit in a high quality superconducting microwave cavity offers the opportunity to perform the first layer of error correction in a single device. We use a 3-wave mixing coupling element to engineer a programmable beamsplitter interaction between two bosonic modes separated by more than an octave in frequency. We then introduce a new protocol to realize a hybrid controlled-SWAP operation in the regime $g_bsapproxchi$, in which a transmon provides the control bit for the SWAP of two bosonic modes.
  arXiv  Detail & Related papers  (2022-12-22T18:07:29Z)
• 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)
• Unimon qubit [42.83899285555746]
  Superconducting qubits are one of the most promising candidates to implement quantum computers. Here, we introduce and demonstrate a superconducting-qubit type, the unimon, which combines the desired properties of high non-linearity, full insensitivity to dc charge noise, insensitivity to flux noise, and a simple structure consisting only of a single Josephson junction in a resonator.
  arXiv  Detail & Related papers  (2022-03-11T12:57:43Z)
• Preparation of excited states for nuclear dynamics on a quantum computer [117.44028458220427]
  We study two different methods to prepare excited states on a quantum computer. We benchmark these techniques on emulated and real quantum devices. These findings show that quantum techniques designed to achieve good scaling on fault tolerant devices might also provide practical benefits on devices with limited connectivity and gate fidelity.
  arXiv  Detail & Related papers  (2020-09-28T17:21:25Z)

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.