GHz-rate all-fiber active polarization state analyzer for quantum protocols

• URL: http://arxiv.org/abs/2607.09597v1
• Date: Fri, 10 Jul 2026 16:54:11 GMT
• Title: GHz-rate all-fiber active polarization state analyzer for quantum protocols
• Abstract summary: We demonstrate a GHz-rate all-fiber polarization state analyzer enabling active, trial-by-trial reconfiguration of the measurement basis.<n>The state analyzer is based on a fiber Sagnac interferometer incorporating a lithium niobate electro-optic phase modulator, built entirely using off-the-shelf fiber-optic components.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Active selection of the measurement basis underpins quantum protocols including device-independent quantum key distribution, quantum teleportation with active feed-forward, and Bell tests. High-speed operation is crucial to minimize the latency between consecutive measurement choices, enabling faster protocol execution and higher achievable communication rates. Here, we demonstrate a GHz-rate all-fiber polarization state analyzer enabling active, trial-by-trial reconfiguration of the measurement basis, which we validate by performing a CHSH Bell test. The state analyzer is based on a fiber Sagnac interferometer incorporating a lithium niobate electro-optic phase modulator, built entirely using off-the-shelf fiber-optic components. Operating at a nominal repetition rate of 1 GHz, the system performs dynamic polarization measurements for the CHSH Bell test, achieving polarization visibilities up to 99% and a violation of $S = 2.6975 \pm 0.0005$, certifying entanglement at an unprecedented rate. Furthermore, the system demonstrates excellent long-term stability, preserving the Bell-inequality violation for more than 6 hours without realignment. These results establish the proposed state analyzer as a versatile, scalable platform for quantum communication protocols requiring fast, reconfigurable polarization-state measurements.

Related papers

• Gigahertz-rate thin-film lithium niobate receiver for time-bin quantum communication [27.308408027453012]
  Device is capable of high-speed electro-optic manipulation of time-bin encoded quantum states.<n>System achieves stable finite-size secure key rates exceeding 25 kbit/s over 12 hours of continuous operation.
  arXiv  Detail & Related papers  (2026-04-17T20:51:57Z)
• Continual Quantum Architecture Search with Tensor-Train Encoding: Theory and Applications to Signal Processing [68.35481158940401]
  CL-QAS is a continual quantum architecture search framework.<n>It mitigates challenges of costly encoding amplitude and forgetting in variational quantum circuits.<n>It achieves controllable robustness expressivity, sample-efficient generalization, and smooth convergence without barren plateaus.
  arXiv  Detail & Related papers  (2026-01-10T02:36:03Z)
• Taming Recoil Effect in Cavity-Assisted Quantum Interconnects [1.2233362977312945]
  We derive an analytical model for evaluating the motion-induced infidelity in remote entanglement generation protocols.<n>Our results establish a concrete path towards fault-tolerant quantum networking with scalable trapped-atom qubit systems.
  arXiv  Detail & Related papers  (2025-02-20T18:59:11Z)
• Continuous Automatic Polarization Channel Stabilization from Heterodyne Detection of Coexisting Dim Reference Signals [5.602886645159814]
  Quantum networking continues to encode information in polarization states due to ease and precision. variable environmental polarization transformations induced by deployed fiber need correction for deployed quantum networking. We present a new method for automatic polarization compensation ( APC) and demonstrate its performance on a metropolitan quantum network.
  arXiv  Detail & Related papers  (2024-11-22T18:58:01Z)
• Universal quantum operations and ancilla-based readout for tweezer clocks [3.2810235099960297]
  We show universal quantum operations and ancilla-based readout for ultranarrow optical transitions of neutral atoms. Our work lays the foundation for hybrid processor-clock devices with neutral atoms and points to a future of practical applications for quantum processors linked with quantum sensors.
  arXiv  Detail & Related papers  (2024-02-25T23:35:36Z)
• System Characterization of Dispersive Readout in Superconducting Qubits [37.940693612514984]
  We introduce a single protocol to measure the dispersive shift, resonator linewidth, and drive power used in the dispersive readout of superconducting qubits. We find that the resonator linewidth is poorly controlled with a factor of 2 between the maximum and minimum measured values. We also introduce a protocol for measuring the readout system efficiency using the same power levels as are used in typical qubit readout.
  arXiv  Detail & Related papers  (2024-02-01T08:15:16Z)
• Finite Pulse-Time Effects in Long-Baseline Quantum Clock Interferometry [45.73541813564926]
  We study the interplay of the quantum center-of-mass $-$ that can become delocalized $-$ together with the internal clock transitions. We show at the example of a Gaussian laser beam that the proposed quantum-clock interferometers are stable against perturbations from varying optical fields.
  arXiv  Detail & Related papers  (2023-09-25T18:00:03Z)
• 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)
• Dissipative preparation and stabilization of many-body quantum states in a superconducting qutrit array [55.41644538483948]
  We present and analyze a protocol for driven-dissipatively preparing and stabilizing a manifold of quantum manybody entangled states. We perform theoretical modeling of this platform via pulse-level simulations based on physical features of real devices. Our work shows the capacity of driven-dissipative superconducting cQED systems to host robust and self-corrected quantum manybody states.
  arXiv  Detail & Related papers  (2023-03-21T18:02:47Z)
• Towards Fully Passive Time-Bin Quantum Key Distribution over Moving Free-Space Channels [36.136619420474766]
  Quantum information in photonic time-bin states is typically considered impractical for moving free-space quantum communication.<n>We demonstrate a novel approach using reference frame independent time-bin quantum key distribution.<n>The scheme can be readily applied over various spatially multi-mode and fluctuating channels involving rapidly moving platforms.
  arXiv  Detail & Related papers  (2023-02-10T03:53:21Z)
• Improving Short-Term Stability in Optical Lattice Clocks by Quantum Nondemolition Measurements [0.0]
  We propose a multimeasurement estimation protocol for Quantum Nondemolition (QND) measurements in a Rabi clock interferometer. The protocol exploits the correlations between multiple non-destructive measurements of the initially prepared coherent spin state.
  arXiv  Detail & Related papers  (2021-09-17T09:09:23Z)
• Fast high-fidelity single-qubit gates for flip-flop qubits in silicon [68.8204255655161]
  flip-flop qubit is encoded in the states with antiparallel donor-bound electron and donor nuclear spins in silicon. We study the multilevel system that is formed by the interacting electron and nuclear spins. We propose an optimal control scheme that produces fast and robust single-qubit gates in the presence of low-frequency noise.
  arXiv  Detail & Related papers  (2021-01-27T18:37:30Z)

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.