Relative Wavefront Errors in Continuous-Variable Quantum Communication

• URL: http://arxiv.org/abs/2508.09491v1
• Date: Wed, 13 Aug 2025 04:52:45 GMT
• Title: Relative Wavefront Errors in Continuous-Variable Quantum Communication
• Authors: Nathan K. Long, John Wallis, Alex Frost, Benjamin P. Dix-Matthews, Sascha W. Schediwy, Kenneth J. Grant, Robert Malaney,
• Abstract summary: This work provides experimental evidence that relative WFEs are present in some circumstances and that standard assumptions in CV-QKD deployments may need to be revisited.<n>In addition, we demonstrate how turbulence can affect the detailed form of the relative WFEs, thereby indicating that long-range links like terrestrial-satellite channels are likely impacted more than short-range terrestrial-only channels.
• Score: 0.18846515534317265
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: When undertaking continuous-variable quantum key distribution (CV-QKD) across atmospheric channels, strong classical local oscillators (LOs) are often polarization-multiplexed with the weak quantum signals for coherent measurement at the receiver. Although the wavefronts of the quantum signal and LO are often assumed to experience the same distortion across channels, previous theoretical work has shown that they can experience differential distortions, resulting in relative wavefront errors (WFEs). Such errors have previously been shown to limit CV-QKD performance, in some cases leading to zero secure key rates. In this work, for the first time, we provide strong experimental evidence that relative WFEs are present in some circumstances and that standard assumptions in CV-QKD deployments may need to be revisited. In addition, we demonstrate how turbulence can affect the detailed form of the relative WFEs, thereby indicating that long-range links like terrestrial-satellite channels are likely impacted more than short-range terrestrial-only channels.

Related papers

• Secret Key Rate Limits in Coexisting Classical-Quantum Optical Links [0.0]
  We derive expressions for evaluating the accumulated interference power from coexisting classical signals in a quantum frequency channel.<n>Our model enables effective design of classical-quantum systems in single-mode fibers.
  arXiv  Detail & Related papers  (2026-02-25T08:08:52Z)
• Shortcuts to adiabaticity, unexciting backgrounds, and reflectionless potentials [45.88028371034407]
  We exploit the analogy with one-dimensional quantum mechanics, and the well known correspondence between Bogoliubov coefficients in the QHO and transmission/reflection amplitudes in scattering theory.<n>We show how STA completions can be understood in terms of the anti-squeezing operator.
  arXiv  Detail & Related papers  (2026-01-16T13:02:37Z)
• Quantum Wavefront Correction via Machine Learning for Satellite-to-Earth CV-QKD [0.456504487386796]
  State-of-the-art free-space continuous-variable quantum key distribution (CV-QKD) protocols use phase reference pulses to modulate the wavefront of a real local oscillator at the receiver.<n>It is normally assumed that the wavefront distortion in these phase reference pulses is identical to the wavefront distortion in the quantum signals, which are multiplexed during transmission.<n>In many real-world deployments, there can exist a relative wavefront error (WFE) between the reference pulses and quantum signals, which can severely limit secure key transfer in satellite-to-Earth CV-QKD.<n>We
  arXiv  Detail & Related papers  (2025-08-14T04:03:07Z)
• Bayesian Quantum Amplitude Estimation [49.1574468325115]
  We present BAE, a problem-tailored and noise-aware Bayesian algorithm for quantum amplitude estimation.<n>In a fault tolerant scenario, BAE is capable of saturating the Heisenberg limit; if device noise is present, BAE can dynamically characterize it and self-adapt.<n>We propose a benchmark for amplitude estimation algorithms and use it to test BAE against other approaches.
  arXiv  Detail & Related papers  (2024-12-05T18:09:41Z)
• Limitations to Dynamical Error Suppression and Gate-Error Virtualization from Temporally Correlated Nonclassical Noise [0.0]
  We study a minimal exactly solvable single-qubit model under Gaussian quantum dephasing noise.<n>For digital periodic control, we prove that the gate fidelity saturates at a value that is strictly smaller than the one attainable in the absence of control history.<n>We find that only if decoupling can keep the qubit highly pure over a timescale larger than the correlation time of the noise, the bath approximately converges to its original statistics.
  arXiv  Detail & Related papers  (2024-07-05T18:00:00Z)
• The Stability of Gapped Quantum Matter and Error-Correction with Adiabatic Noise [0.0]
  We argue that a quantum code can recover from adiabatic noise channels, corresponding to random adiabatic drift of code states through the phase. We show examples in which quantum information can be recovered by using stabilizer measurements and Pauli feedback, even up to a phase boundary.
  arXiv  Detail & Related papers  (2024-02-22T19:00:00Z)
• Harnessing high-dimensional temporal entanglement using limited interferometric setups [41.94295877935867]
  We develop the first complete analysis of high-dimensional entanglement in the polarization-time-domain. We show how to efficiently certify relevant density matrix elements and security parameters for Quantum Key Distribution. We propose a novel setup that can further enhance the noise resistance of free-space quantum communication.
  arXiv  Detail & Related papers  (2023-08-08T17:44:43Z)
• Round-robin differential phase-time-shifting protocol for quantum key distribution: theory and experiment [58.03659958248968]
  Quantum key distribution (QKD) allows the establishment of common cryptographic keys among distant parties. Recently, a QKD protocol that circumvents the need for monitoring signal disturbance, has been proposed and demonstrated in initial experiments. We derive the security proofs of the round-robin differential phase-time-shifting protocol in the collective attack scenario. Our results show that the RRDPTS protocol can achieve higher secret key rate in comparison with the RRDPS, in the condition of high quantum bit error rate.
  arXiv  Detail & Related papers  (2021-03-15T15:20:09Z)
• Crosstalk Suppression for Fault-tolerant Quantum Error Correction with Trapped Ions [62.997667081978825]
  We present a study of crosstalk errors in a quantum-computing architecture based on a single string of ions confined by a radio-frequency trap, and manipulated by individually-addressed laser beams. This type of errors affects spectator qubits that, ideally, should remain unaltered during the application of single- and two-qubit quantum gates addressed at a different set of active qubits. We microscopically model crosstalk errors from first principles and present a detailed study showing the importance of using a coherent vs incoherent error modelling and, moreover, discuss strategies to actively suppress this crosstalk at the gate level.
  arXiv  Detail & Related papers  (2020-12-21T14:20:40Z)
• Quantum-enabled communication without a phase reference [1.14219428942199]
  A phase reference has been a standard requirement in continuous-variable quantum sensing and communication protocols. We show that quantum communication and entanglement-assisted communication without a phase reference are possible, when a short-time memory effect is present.
  arXiv  Detail & Related papers  (2020-10-22T18:19:00Z)
• Probing the coherence of solid-state qubits at avoided crossings [51.805457601192614]
  We study the quantum dynamics of paramagnetic defects interacting with a nuclear spin bath at avoided crossings. The proposed theoretical approach paves the way to designing the coherence properties of spin qubits from first principles.
  arXiv  Detail & Related papers  (2020-10-21T15:37:59Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)
• Using Quantum Metrological Bounds in Quantum Error Correction: A Simple Proof of the Approximate Eastin-Knill Theorem [77.34726150561087]
  We present a proof of the approximate Eastin-Knill theorem, which connects the quality of a quantum error-correcting code with its ability to achieve a universal set of logical gates. Our derivation employs powerful bounds on the quantum Fisher information in generic quantum metrological protocols.
  arXiv  Detail & Related papers  (2020-04-24T17:58:10Z)
• Protecting quantum Fisher information in correlated quantum channels [1.2183405753834562]
  We investigate Quantum Fisher information (QFI) when the consecutive actions of a quantum channel on the sequence of qubits have partial classical correlations. For the Bell-type probe states, the classical correlations on consecutive actions of the depolarizing and phase flip channels can be harnessed to improve QFI. For a more general parameterization form of the probe states, the advantage of using initial correlated system on improving QFI can also be remained in a wide regime of the correlated quantum channels.
  arXiv  Detail & Related papers  (2020-03-06T03:02:58Z)

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.