High-Rate Free-Space Continuous-Variable QKD with Self-Referenced Passive State Preparation

• URL: http://arxiv.org/abs/2604.27299v2
• Date: Thu, 07 May 2026 06:30:01 GMT
• Title: High-Rate Free-Space Continuous-Variable QKD with Self-Referenced Passive State Preparation
• Abstract summary: Continuous-variable quantum key distribution (CVQKD) using passive state preparation (PSP) offers low-cost, high-rate secure communication.<n>Existing PSP-CVQKD scheme with a transmitted local oscillator has high photon leakage noise and poor stability.
• Score: 0.4609009658585936
• License: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Abstract: Continuous-variable quantum key distribution (CVQKD) using passive state preparation (PSP) offers low-cost, high-rate secure communication. However, the existing PSP-CVQKD scheme with a transmitted local oscillator has high photon leakage noise and poor stability, making it unsuitable for high-loss transmission. In this work, for the first time, we propose and implement a local local oscillator (LLO) CVQKD system using a self-referenced (SR) PSP scheme, and give a theoretical proof of the equivalence of the PSP and GMCS protocol using temporal-mode theory. By employing the novel self-referenced pilot scheme to achieve high-precision time-varying frequency and phase compensation algorithms, we significantly improve the system' s signal-to-noise ratio and stability. The system achieves a record-high asymptotic secret key rate of 10.34 Mbps over a free-space channel with up to 23.5 dB loss, while maintaining low excess noise and robust performance under turbulent conditions. This work establishes the feasibility of SR-LLO CVQKD, providing a practical pathway toward secure, high-rate quantum communication in realistic environments.

Related papers

• Experimental Demonstration of Free-Space Unidimensional Continuous-Variable Quantum Key Distribution Under High Detector Noise [0.10874100424278171]
  We experimentally demonstrate a free-space Gaussian-modulated UD-CVQKD system operating under a high detector electronic-noise regime.<n>A maximum secret key rate of 270 kbps is achieved at an optimal modulation variance of 11.57.<n>This study demonstrates the practical feasibility of free-space UD-CVQKD in realistic high electronic-noise detection constraints.
  arXiv  Detail & Related papers  (2026-06-05T12:17:17Z)
• 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)
• Enhancing Long-distance Continuous-variable Quantum-key-distribution with an Error-correcting Relay [37.19059223604783]
  Noiseless linear amplifiers (NLAs) serve as an effective means to enable long-distance continuous-variable (CV) quantum key distribution (QKD)<n>We combine these two protocols to simultaneously compensate for thermal-loss effects and suppress phase noise, thereby enabling CV QKD that surpasses the repeaterless bound, the fundamental rate-distance limit, for repeaterless quantum communication systems.
  arXiv  Detail & Related papers  (2025-12-12T02:08:11Z)
• PASS-Enhanced MEC: Joint Optimization of Task Offloading and Uplink PASS Beamforming [67.78883135636657]
  pinching-antenna system (PASS)-enhanced mobile edge computing (MEC) architecture is investigated.<n>PASS establishes short-distance line-of-sight (LoS) links while effectively mitigating the significant path loss and potential signal blockage.<n>We formulate a network latency minimization problem to joint optimize uplink PASS beamforming and task offloading.
  arXiv  Detail & Related papers  (2025-10-27T03:04:46Z)
• High-Performance Fully Passive Discrete-State Continuous-Variable Quantum Key Distribution With Local Local Oscillator [11.547596386054364]
  We propose and demonstrate a fully passive discrete-state continuous-variable quantum key distribution (CV-QKD)<n>The CV-QKD system achieves a maximum transmission length of 100 km with a repetition rate of 1 GHz using specially designed phase rotation and discretization methods.<n>Our protocol is expected to play an important role in the quantum metropolitan area networks and quantum access networks with high realistic security.
  arXiv  Detail & Related papers  (2025-07-31T08:14:54Z)
• High-rate self-referenced continuous-variable quantum key distribution over high-loss free-space channel [4.616309024935511]
  This paper introduces a continuous-time mode theory for high-precision estimation of time-varying parameters.<n>We demonstrate high-rate secure quantum key distribution over high-loss free-space channels.<n>We also confirm the feasibility of experiments on mildly turbulent atmospheric channels spanning at least 10.5 km using current equipments.
  arXiv  Detail & Related papers  (2025-03-13T08:50:37Z)
• Long distance local local oscillator continuous variable quantum key distribution with digital signal processing [14.339854405226385]
  Continuous variable quantum key distribution (CV-QKD) is widely applied because it can be well combined with standard telecommunication technology.<n>Challenges still persist in practical long-distance transmission, including data sampling and recovery under low signal-to-noise ratio conditions.<n>We propose the least squares fitting algorithm to get more accurate sampling data and complete more accurate phase compensation.
  arXiv  Detail & Related papers  (2025-03-04T08:28:43Z)
• Practical quantum secure direct communication with squeezed states [37.69303106863453]
  We report the first table-top experimental demonstration of a CV-QSDC system and assess its security.<n>This realization paves the way into future threat-less quantum metropolitan networks, compatible with coexisting advanced wavelength division multiplexing (WDM) systems.
  arXiv  Detail & Related papers  (2023-06-25T19:23:42Z)
• Long-distance continuous-variable quantum key distribution over 100 km fiber with local local oscillator [0.6524460254566905]
  Quantum key distribution (QKD) enables two remote parties to share encryption keys with security based on the laws of physics. Here, we report a long-distance CV-QKD experiment with a locally generated local oscillator over a 100 km fiber channel with a total loss of 15.4 dB. This record-breaking distance is achieved by controlling the phase-noise-induced excess noise through a machine-learning framework for carrier recovery and optimizing the modulation variance.
  arXiv  Detail & Related papers  (2023-05-14T13:34:20Z)
• Towards fully-fledged quantum and classical communication over deployed fiber with up-conversion module [47.187609203210705]
  We propose and demonstrate a new method, based on up-conversion assisted receiver, for co-propagating classical light and QKD signals. Our proposal exhibits higher tolerance for noise in comparison to the standard receiver, thus enabling the distribution of secret keys in the condition of 4 dB-higher classical power.
  arXiv  Detail & Related papers  (2021-06-09T13:52:27Z)
• Composably secure data processing for Gaussian-modulated continuous variable quantum key distribution [58.720142291102135]
  Continuous-variable quantum key distribution (QKD) employs the quadratures of a bosonic mode to establish a secret key between two remote parties. We consider a protocol with homodyne detection in the general setting of composable finite-size security. In particular, we analyze the high signal-to-noise regime which requires the use of high-rate (non-binary) low-density parity check codes.
  arXiv  Detail & Related papers  (2021-03-30T18:02:55Z)

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.