Orthogonal Frequency Division Multiplexing Continuous Variable Terahertz Quantum Key Distribution

• URL: http://arxiv.org/abs/2506.22985v1
• Date: Sat, 28 Jun 2025 19:16:29 GMT
• Title: Orthogonal Frequency Division Multiplexing Continuous Variable Terahertz Quantum Key Distribution
• Authors: Mingqi Zhang, Kaveh Delfanazari,
• Abstract summary: We propose a quantum key distribution protocol that encodes quantum information across multiple subcarriers in the terahertz (THz) band.<n>By encoding quantum information across multiple subcarriers, the protocol enhances spectral efficiency and mitigates channel dispersion and atmospheric attenuation.<n>We show secure communication over distances up to 3 m in open air, and up to 26 km in cryogenic or vacuum environments.
• Score: 0.3069335774032178
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We propose a novel continuous-variable quantum key distribution (CVQKD) protocol that employs orthogonal frequency-division multiplexing (OFDM) in the terahertz (THz) band to enable high-throughput and secure quantum communication. By encoding quantum information across multiple subcarriers, the protocol enhances spectral efficiency and mitigates channel dispersion and atmospheric attenuation. We present a comprehensive security analysis under collective Gaussian attacks, considering both terrestrial free-space channels, accounting for humidity-induced absorption, and inter-satellite links, incorporating realistic intermodulation noise. Simulations show secret key rates (SKR) reaching ~72 bits per channel use in open-air conditions. While intermodulation noise imposes trade-offs, optimised modulation variance enables resilience and secure communication range. The maximum terrestrial quantum link extends up to 4.5 m due to atmospheric THz absorption, whereas inter-satellite links can support secure communication over distances exceeding 100 km, owing to minimal propagation channel losses in space. We evaluate the practical implementation of our protocol using recently developed on-chip coherent THz sources based on superconducting Josephson junctions. These compact, voltage-tunable emitters produce wideband coherent radiation, making them ideal candidates for integration in scalable quantum networks. By incorporating their characteristics into our simulations, we assess secure key generation under various environmental conditions. Our results show secure communication over distances up to 3 m in open air, and up to 26 km in cryogenic or vacuum environments. This work advances the prospect of compact, high-capacity CVQKD systems for both terrestrial and space-based THz quantum communication.

Related papers

• Long-distance free-space quantum key distribution with continuous variables [7.304370674075303]
  Continuous-variable quantum key distribution (CVQKD) enables remote users to share high-rate and unconditionally secure secret keys.<n>CVQKD experiments have only been demonstrated indoors or over short outdoor distances.<n>We demonstrate for the first time long-distance free-space quantum key distribution over 7-km inland and 9.6-km maritime atmospheric channels.
  arXiv  Detail & Related papers  (2025-07-29T07:21:24Z)
• Free-space Continuous-variable Quantum Secret Sharing [2.299246827651063]
  Free-space quantum cryptography has the potential to enable global quantum communication.<n>We present a CV-QSS protocol designed for free-space transmission.<n>We show that efficient CV-QSS in free space is indeed achievable.
  arXiv  Detail & Related papers  (2025-03-14T10:17:47Z)
• 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)
• Emulation of satellite up-link quantum communication with entangled photons [75.38606213726906]
  We demonstrate an ultra-bright source of far-non-degenerate entangled photons and perform quantum key distribution in emulated high-loss satellite scenarios.<n>With a loss profile corresponding to that of one of the pioneering Micius up-link experiments, and a terrestrial end user separated by 10km of telecom fibre we achieve secure key accumulation of 5.2kbit in a single overpass in the limit.
  arXiv  Detail & Related papers  (2025-02-05T19:14:55Z)
• Practical hybrid PQC-QKD protocols with enhanced security and performance [44.8840598334124]
  We develop hybrid protocols by which QKD and PQC inter-operate within a joint quantum-classical network. In particular, we consider different hybrid designs that may offer enhanced speed and/or security over the individual performance of either approach.
  arXiv  Detail & Related papers  (2024-11-02T00:02:01Z)
• Experimental composable key distribution using discrete-modulated continuous variable quantum cryptography [1.9464379888286716]
  We present the first experimental demonstration of a four-state DM CVQKD system, successfully generating composable finite-size keys. This accomplishment is enabled by using an advanced security proof. Results mark a significant step toward the large-scale deployment of practical, high-performance, cost-effective, and highly secure quantum key distribution networks.
  arXiv  Detail & Related papers  (2024-10-17T16:05:08Z)
• On-demand transposition across light-matter interaction regimes in bosonic cQED [69.65384453064829]
  Bosonic cQED employs the light field of high-Q superconducting cavities coupled to non-linear circuit elements. We present the first experiment to achieve fast switching of the interaction regime without deteriorating the cavity coherence. Our work opens up a new paradigm to probe the full range of light-matter interaction dynamics within a single platform.
  arXiv  Detail & Related papers  (2023-12-22T13:01:32Z)
• 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)
• Practical quantum secure direct communication with squeezed states [55.41644538483948]
  We report the first table-top experimental demonstration of a CV-QSDC system and assess its security. 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)
• Towards Fully Passive Time-Bin Quantum Key Distribution over Multi-Mode Channels [37.69303106863453]
  Phase stabilization of distant quantum time-bin interferometers is a major challenge for quantum communication networks. We demonstrate a novel approach using reference frame independent time-bin quantum key distribution. This is achieved without any mode filtering, mode sorting, adaptive optics, active basis selection, or active phase alignment.
  arXiv  Detail & Related papers  (2023-02-10T03:53:21Z)
• Millimetre-waves to Terahertz SISO and MIMO Continuous Variable Quantum Key Distribution [0.43748379918040853]
  We show that secure mm-waves and THz QKD can be achieved when the sources and detectors operate at cryogenic temperatures down to T= 4K. Our results may contribute to the efforts to develop next-generation secure wireless communication systems and quantum internet.
  arXiv  Detail & Related papers  (2023-01-11T21:19:33Z)
• Continuous-Variable Measurement-Device-Independent Quantum Key Distribution in Free-Space Channels [0.0]
  We study continuous-variable (CV) quantum key distribution (QKD) in a measurement-device-independent (MDI) configuration over free-space optical (FSO) links. We assess the turbulence regime and provide a composable finite-size key rate analysis of the protocol for FSO links.
  arXiv  Detail & Related papers  (2022-12-13T16:02:35Z)
• 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)
• 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)

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.