EPJ Quantum Technology最新文献

{"title":"Rethinking dual-use in quantum technology","authors":"Michal Krelina,&nbsp;Ulrich Mans","doi":"10.1140/epjqt/s40507-026-00560-5","DOIUrl":"10.1140/epjqt/s40507-026-00560-5","url":null,"abstract":"<div><p>Quantum technologies serve civilian and military purposes at once, a fact usually captured by the contested term “dual-use”. Introducing a topical collection on dual-use quantum technologies, this editorial provides a proposed guidance on the term’s applicability in view of an emerging quantum economy. Quantum technology was dual-use from its origins, in foundational experiments funded and in some cases performed by defence and intelligence agencies; but that history is largely Anglo-American, which is part of why the connection between quantum research and defence is accepted so differently, and so much more recently, in continental Europe. As a concept, “dual-use” describes a status rather than settling any moral question, a point that three of the collected papers reach independently using different lenses. The collection’s ten contributions are a reflection of a wide and diverse sector; they span technology development, strategy, governance, and the ethics of dual-use research.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00560-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of frames on engagement with quantum technology","authors":"Aletta L. Meinsma,&nbsp;Casper J. Albers,&nbsp;Pieter Vermaas,&nbsp;Ionica Smeets,&nbsp;Julia Cramer","doi":"10.1140/epjqt/s40507-026-00549-0","DOIUrl":"10.1140/epjqt/s40507-026-00549-0","url":null,"abstract":"<div><p>Engaging a larger, non-specialist audience with quantum technology poses challenges as the theory underlying quantum technology is very different to what we experience in our everyday lives. Quantum technology is predicted to have a significant impact on society once it matures. This study (<span>(n = 637)</span> adults representative of the Dutch population) examined the effect of different frames on engagement – specifically, information seeking, internal efficacy, general interest and perceived knowledge – with quantum technology. The different frames were: enigmatic, explaining quantum physics, benefit, risk and balanced. Results indicated that framing quantum as enigmatic does not affect engagement, while explaining quantum physics positively influences general interest. Furthermore, emphasising a benefit of quantum technology increases participants’ internal efficacy, whereas highlighting both a benefit and a risk of quantum technology decreases perceived knowledge. Based on these findings, we offer practical advice for science communicators in the field and suggest further research.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00549-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traversing Gaussian and non-Gaussian regimes in photonic quantum simulators: a review","authors":"Dennis Delali Kwesi Wayo,&nbsp;Rodrigo Alves Dias,&nbsp;Masoud Darvish Ganji,&nbsp;Camila Martins Saporetti,&nbsp;Leonardo Goliatt","doi":"10.1140/epjqt/s40507-026-00496-w","DOIUrl":"10.1140/epjqt/s40507-026-00496-w","url":null,"abstract":"<div><p>Quantum photonic simulators are pivotal for designing and analyzing quantum photonic circuits that utilize both continuous-variable (CV) and discrete-variable (DV) encodings. This review critically examines the transition from Gaussian to non-Gaussian photonic models and the computational overhead that emerges from simulating systems with more than 20 modes or photon numbers exceeding 10 per mode. Gaussian states; such as coherent and squeezed states, are modeled efficiently using first-moment vectors and covariance matrices of dimension <span>(2n times 2n)</span>, where <i>n</i> is the number of modes. Non-Gaussian elements like the cubic phase gate <span>(U = exp (i gamma hat{x}^{3}))</span> and photon-subtracted states demand full Fock space representations and scale exponentially with photon number <span>(d^{2})</span>, where <i>d</i> is the Hilbert space dimension. We analyze simulators including <span>Strawberry Fields</span>, <span>Piquasso</span>, and <span>Perceval</span>, benchmarking their support for tensor networks (bond dimension D &gt;100), GPU acceleration, thus NVIDIA A100 with 1555 GB/s bandwidth, and SoC implementations such as Edge TPU with 8 TFLOPS. Special focus is given to noise models such as photon loss with transmissivity <i>η</i>, thermal noise modeled with <span>(bar{n} = 1.5)</span>, and dark count Poisson distributions (<span>(lambda = 0.1)</span>). The review underscores scalable techniques and hybrid quantum-classical workflows vital for near-term photonic quantum computing.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00496-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrometry of extremely-low frequencies from kHz to sub-Hz with a Rydberg-atom sensor","authors":"Aveek Chandra,&nbsp;Narongrit Paensin,&nbsp;Rainer Dumke","doi":"10.1140/epjqt/s40507-026-00550-7","DOIUrl":"10.1140/epjqt/s40507-026-00550-7","url":null,"abstract":"<div><p>Rydberg-atom electric field sensing has shown great potential from near-DC to THz with state-of-the-art measurement metrics realized in sensitivity, phase extraction, multi-band receptivity, etc. While Rydberg-atom sensors have shown exceptional performance in the GHz regime, low-frequency operation has remained challenging because of electric-field-screening in conventional vapor cells, which suppresses externally applied fields. We overcome this limitation by combining auxiliary modulation and lock-in detection with a paraffin-coated vapor cell, and demonstrate an electrode-free, wideband method for sensing frequencies, ranging from 0.5 Hz to 10 kHz. Our work extends Rydberg-atom sensor’s range to VLF, ULF, SLF, ELF and sub-ELF frequency bands. In our method, high state-of-the-art sensitivities have been achieved - 819 <span>(mu text{V/cm}/sqrt{text{Hz}})</span> for 1 Hz, 33 <span>(mu text{V/cm}/sqrt{text{Hz}})</span> for 10 Hz, 10 <span>(mu text{V/cm}/sqrt{text{Hz}})</span> for 100 Hz and 2 <span>(mu text{V/cm}/sqrt{text{Hz}})</span> for 1 kHz.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00550-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148781958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Byzantine-repeater-aware mediated multi-party QKD in untrusted networks: a corrected-frame finite-key security framework via entropy accumulation","authors":"Hamza Sohail,&nbsp;Burhan Ul Islam Khan,&nbsp;Aabid A. Mir,&nbsp;Khang Wen Goh,&nbsp;Dwi Sudarno Putra,&nbsp;Mesith Chaimanee","doi":"10.1140/epjqt/s40507-026-00544-5","DOIUrl":"10.1140/epjqt/s40507-026-00544-5","url":null,"abstract":"<div><p>Mediated multi-party quantum key distribution (M-MQKD) is studied for repeater-assisted quantum networks with an untrusted repeater layer and end users restricted to single-qubit local operations and one-way quantum reception. Building on the 1D+star mediated construction, the repeater path is treated as an untrusted measurement layer and the security analysis adopts a corrected-frame GHZ model. Under authenticated timing windows, trusted user-side measurements, a calibrated Check observable, and an explicit public-reconciliation transcript, we establish a corrected-frame finite-key theorem yielding a conference-key length bound from two experimentally accessible statistics: Share-mode disagreement and Check-mode parity-violation. The virtual phase-error variable for privacy amplification is related to the corrected-frame Check parity observable by a stabilizer-complementarity argument with quantum side information, while the entropy term in entropy accumulation is replaced by a predeclared affine lower bound on <span>(1- h_{2} (x))</span>. Error-correction leakage is accounted for through a designated-leader pairwise reconciliation transcript, including syndrome traffic, verification tags, and auxiliary public messages. The protocol is hardened by announcement-consistency traps, salted commit-then-open commitments over modes and parameter-estimation outcomes, randomized reveal order, and authenticated timing windows. These mechanisms detect or exclude dishonest classical disclosures before parameter estimation and treat trap failures as an abort/detection statistic rather than an unproved entropy penalty. The framework gives an auditable finite-key extraction rule as a function of observed error rates, finite-sampling radii, reconciliation leakage, EAT finite-size penalties, trap thresholds, and commitment length. Numerical evaluation maps rate-security trade-offs and gives parameter-selection guidance, supporting resilient infrastructure for secure multi-party quantum communication.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00544-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling detector response for accurate calibration of single-photon detectors under pulsed single-photon illumination","authors":"Hristina Georgieva,&nbsp;Edouard Ivanov,&nbsp;Petr Stepanov,&nbsp;Marco López,&nbsp;Stefan Kück","doi":"10.1140/epjqt/s40507-026-00540-9","DOIUrl":"10.1140/epjqt/s40507-026-00540-9","url":null,"abstract":"<div><p>We present an empirical model describing the detection response of single-photon detectors under pulsed illumination from a single-photon source based on a quantum dot. The model does not rely on assumptions about the recovery dynamics, but incorporates measured recovery functions to predict the effective detection efficiency. This model was successfully validated through a calibration of a superconducting nanowire single-photon detector at photon fluxes of up to 19 million photons per second at a wavelength of 929 nm. Calibrations of three silicon single-photon avalanche detectors with different dead times revealed deviations from the model predictions, suggesting an unaccounted influence of the different electronic design on the detector performance. Owing to its flexibility, the proposed model enables accurate estimation of photon fluxes from single-photon emitters and provides a practical tool for evaluating loss budgets of each component and therefore of entire quantum optical systems, thereby improving the overall system performance.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00540-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Krylov complexity as a cryptographic resource: eavesdropper detection in quantum key distribution via operator-growth channel fingerprints","authors":"Daniel Süß","doi":"10.1140/epjqt/s40507-026-00541-8","DOIUrl":"10.1140/epjqt/s40507-026-00541-8","url":null,"abstract":"<div><p>I present a physical-layer monitoring framework for quantum key distribution (QKD) implementations based on Krylov/operator-growth diagnostics. Running alongside standard parameter estimation, privacy amplification, and composable security proofs, it addresses a focused question: whether the temporal correlation structure of an observed quantum bit error rate (QBER) stream carries additional information about physical channel perturbations. Within a specified local-Hamiltonian channel model, the Lanczos coefficients of the channel Liouvillian define an operator-growth autocorrelation template, and deviations from it serve as anomaly scores for implementation monitoring.</p><p>For the model studied here, the QBER autocorrelation relates to the operator autocorrelation through a proportionality relation, <span>(C_{mathrm{QBER}}(tau )=alpha (N)C_{mathrm{op}}(tau ))</span>, with <span>(alpha (N))</span> an explicitly specified calibration factor. Local Hamiltonian perturbations generically distort the associated Krylov fingerprint once the perturbation reaches the support of the monitored observable, consistent with the locality of the Lanczos recursion and with Lieb–Robinson bounds.</p><p>The resulting three-layer pipeline combines adaptive frequency filtering, Krylov-template extraction, and calibrated slope detection. On simulated BB84-like QBER data with realistic hardware noise, the detector achieves high anomaly discrimination under the tested perturbation classes (<span>(mathrm{AUC}=0.9899)</span>). On <span>(181{,}606)</span> public QBER measurements from a deployed fiber-optic QKD system, it yields a 4.5% clean-test alarm rate against a 5% design target and detects injected perturbations with 96.0% sensitivity at <span>(Delta mathrm{QBER}={+}0.5%)</span> (<span>(mathrm{AUC}=0.981)</span>). Certification of final key secrecy remains governed by the underlying QKD protocol, parameter estimation, finite-key analysis, and privacy amplification.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00541-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implementation of high-fidelity two-qubit gates across separate superconducting quantum chips via a bus resonator","authors":"Shu-Ya Wang,&nbsp;Dong-Sheng Wang,&nbsp;Xiao-Han Yu,&nbsp;Bo Zhao,&nbsp;Wei-Long Wang,&nbsp;Hui-Hui Sun,&nbsp;Li-Xin Wang,&nbsp;Fu-Dong Liu,&nbsp;Xu-Yan Qi,&nbsp;Zheng Shan","doi":"10.1140/epjqt/s40507-026-00527-6","DOIUrl":"10.1140/epjqt/s40507-026-00527-6","url":null,"abstract":"<div><p>High-fidelity quantum interconnection remains a critical challenge for scaling up superconducting quantum chips. Here, we realize a simple fixed coupling scheme to achieve high-fidelity two-qubit gate operation across separate superconducting quantum chips. In this scheme, qubit-qubit coupling between separate chips can be realized via exchange interaction mediated by a bus resonator. By merely tuning the frequency of a single qubit, the resonant mode of the bus resonator can be modulated, enabling high-quality and stable quantum interconnection across different chips. Consequently, the experimentally implemented two-qubit gate operations between separate chips exhibit excellent performance, with a maximum two-qubit CZ gate fidelity reaching 99.57%. This work lays a technical foundation for the realization of high-fidelity chip-to-chip quantum interconnection, which facilitates the development of large-scale superconducting quantum chips with high fidelity.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00527-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Communicating dual-use quantum technologies across science, politics, the military, and business","authors":"Kristian H. Nielsen,&nbsp;Esben Rohan Christensen","doi":"10.1140/epjqt/s40507-026-00533-8","DOIUrl":"10.1140/epjqt/s40507-026-00533-8","url":null,"abstract":"<div><p>Quantum technologies are increasingly framed as dual-use, raising concerns about civilian benefits alongside potential military and security applications. This paper examines how dual-use quantum technologies are communicatively constructed across four functionally differentiated domains: science, politics, the military, and business. Rather than treating dual-use as an inherent property of technology, we conceptualize it as a communicative category through which uncertainty, responsibility, and future expectations are negotiated. Drawing on Niklas Luhmann’s systems theory, we analyze a qualitative corpus of scientific publications, policy documents, military strategy reports, and business communications. We show that shared terms such as dual-use, security, and quantum advantage circulate across domains but acquire distinct meanings as they are re-embedded within domain-specific communicative codes. These translations generate both resonance and dissonance, producing structured misalignment rather than convergence. The paper contributes to our understanding of dual-use quantum technologies by reconstructing domain-specific articulations of dual-use, explaining their divergence through functional differentiation, and highlighting implications for responsibility, authority, and governance.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00533-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric entanglement-assisted quantum error-correcting MDS codes of physical qubits (p^{s}) over (mathbb{F}_{p^{m}})","authors":"Hai Q. Dinh,&nbsp;Bac T. Nguyen,&nbsp;Hiep L. Thi,&nbsp;Luong Tran Thi,&nbsp;W. Yamaha","doi":"10.1140/epjqt/s40507-026-00503-0","DOIUrl":"10.1140/epjqt/s40507-026-00503-0","url":null,"abstract":"<div><p>In this paper, we construct entanglement-assisted quantum error-correcting codes (EAQEC codes) of physical qubits <span>(p^{s})</span> over <span>(mathbb{F}_{p^{m}})</span>. We compare our EAQEC codes with all known EAQEC codes to see that our EAQEC codes are new in the sense that their parameters are different from all the previous constructions. If we fix the physical qubits and the logical qubits of EAQEC codes, many of them have larger quantum distances than the well known EAQEC codes in the literature. Moreover, some of our EAQEC codes achieve larger quantum distances while requiring fewer or the same number of entangled bits compared with existing EAQEC codes when the numbers of physical qubits and logical qubits are fixed. We construct asymmetric entanglement-assisted quantum error-correcting (AEAQEC) MDS codes of physical qubits <span>(p^{s})</span> over <span>(mathbb{F}_{p^{m}})</span>. When the physical qubits of the AEAQEC codes is fixed, many of our AEAQEC codes have a significantly larger number of quantum distances compared to all previously constructed AEAQEC codes. We also provide a version of Singleton bound for all AEAQEC codes.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjqt/s40507-026-00503-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}