EPJ Quantum Technology最新文献

Numerical model of N-level cascade systems for atomic Radio Frequency sensing applications 用于原子射频传感应用的 N 级级联系统数值模型

IF 5.8 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2024-11-18 DOI: 10.1140/epjqt/s40507-024-00291-5

Liam W. Bussey, Yogeshwar B. Kale, Samuel Winter, Fraser A. Burton, Yu-Hung Lien, Kai Bongs, Costas Constantinou

{"title":"Numerical model of N-level cascade systems for atomic Radio Frequency sensing applications","authors":"Liam W. Bussey, Yogeshwar B. Kale, Samuel Winter, Fraser A. Burton, Yu-Hung Lien, Kai Bongs, Costas Constantinou","doi":"10.1140/epjqt/s40507-024-00291-5","DOIUrl":"10.1140/epjqt/s40507-024-00291-5","url":null,"abstract":"<div><p>A ready-to-use numerical model has been developed for the atomic ladder (cascade) systems which are widely exploited in Rydberg Radio Frequency (RF) sensors. The model has been explicitly designed for user convenience and to be extensible to arbitrary N-level non-thermal systems. The versatility and adaptability of the model is validated up to 4-level atomic systems by direct comparison with experimental results from the prior art. The numerical model provides a good approximation to the experimental results and provides experimentalists with a convenient ready-to-use model to optimise the operation of an N-level Rydberg RF sensor. Current sensors exploit the 4-level atomic systems based on alkali metal atoms which require visible frequency lasers and these can be expensive and also suffer from high attenuation within optical fiber. The ability to quickly and simply explore more complex N-level systems offers the potential to use cheaper and lower-loss near-infrared lasers.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"11 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-024-00291-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664472","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}

引用次数: 0

Microwave electrometry with bichromatic electromagnetically induced transparency in Rydberg atoms 里德伯原子中双色电诱导透明的微波电测量

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-07-14 DOI: 10.1140/epjqt/s40507-023-00184-z

Mingzhi Han, He Hao, Xiaoyun Song, Zheng Yin, Michal Parniak, Zhengmao Jia, Yandong Peng

引用次数: 0

Modular source for near-infrared quantum communication 近红外量子通信模块源

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-07-12 DOI: 10.1140/epjqt/s40507-023-00185-y

Federico Berra, Costantino Agnesi, Andrea Stanco, Marco Avesani, Sebastiano Cocchi, Paolo Villoresi, Giuseppe Vallone

{"title":"Modular source for near-infrared quantum communication","authors":"Federico Berra, Costantino Agnesi, Andrea Stanco, Marco Avesani, Sebastiano Cocchi, Paolo Villoresi, Giuseppe Vallone","doi":"10.1140/epjqt/s40507-023-00185-y","DOIUrl":"10.1140/epjqt/s40507-023-00185-y","url":null,"abstract":"<div><p>We present a source of states for Quantum Key Distribution (QKD) based on a modular design exploiting the iPOGNAC, a stable, low-error, and calibration-free polarization modulation scheme, for both intensity and polarization encoding. This source is immune to the security vulnerabilities of other state sources such as side channels and some quantum hacking attacks. Remarkably, our intensity modulation scheme allows full tunability of the intensity ratio between the decoy and signal states, and mitigates patterning effects. The source was implemented and tested at the near-infrared optical band around 800 nm, of particular interest for satellite-based QKD. Furthermore, the modularity of the source simplifies its development, testing, and qualification, especially for space missions. For these reasons, our work paves the way for the development of the second generation of QKD satellites that can guarantee excellent performances at higher security levels.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00185-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4499981","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}

引用次数: 0

Quantum encryption in phase space with displacement operators 具有位移算子的相空间量子加密

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-29 DOI: 10.1140/epjqt/s40507-023-00183-0

Randy Kuang, Adrian Chan

{"title":"Quantum encryption in phase space with displacement operators","authors":"Randy Kuang, Adrian Chan","doi":"10.1140/epjqt/s40507-023-00183-0","DOIUrl":"10.1140/epjqt/s40507-023-00183-0","url":null,"abstract":"<div><p>In photonic computing, the quantum systems consist of coherent states and squeezed coherent states. Common quantum gates found in these systems are: phase shift, displacement, and squeezing gates. These gates are all unitary and reversible. Outside of quantum systems, coherent states also plays a significant role in coherent optical communications with speeds of hundreds of gigabits per second. Secure optical communications is generally implemented at the data layer with classical symmetric encryption such as Advanced Standard Encryption or AES. This inevitably allows any wiretapping to capture the transmitted data either in the plaintext mode or in the encrypted ciphertext mode in the optical infrastructure. The recent and rapid developments in Quantum computing further lift up the need for quantum secure communications in the optical infrastructure. This paper proposes a novel quantum encryption in the coherent optical domain utilizing a displacement operator and implementing with IQ-MZM optical modules, called Quantum Encryption in Phase Space or QEPS. The communication peers share a secret used to seed cryptographic pseudo random number generators to produce a synchronized random number at both the transmitter and receiver. The synchronized random numbers are used to establish displacement operators to encrypt the coherent states at the transmission and decrypt the cipher coherent states at the receiver. Therefore, malicious parties tapping along the fibre line would not extract the message in transit from optical domain due to a high Bit Error Rate or BER. The optimal displacement operator is split into a standard 16-QAM and a random phase shift operator to enhance the transmission security. We analysis the transmission security with the wiretap channel model for semantic security. We have simulated the QEPS encryption and decryption for two data modulation schemes: QPSK and 16-QAM over 80 km for transmission speeds of 56 Gbps for QPSK and 112 Gbps for 16-QAM.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00183-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5119462","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}

引用次数: 2

Optimal quantum state tomography with noisy gates 带噪声门的最佳量子态层析成像

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-28 DOI: 10.1140/epjqt/s40507-023-00181-2

Violeta N. Ivanova-Rohling, Niklas Rohling, Guido Burkard

{"title":"Optimal quantum state tomography with noisy gates","authors":"Violeta N. Ivanova-Rohling, Niklas Rohling, Guido Burkard","doi":"10.1140/epjqt/s40507-023-00181-2","DOIUrl":"10.1140/epjqt/s40507-023-00181-2","url":null,"abstract":"<div><p>Quantum state tomography (QST) represents an essential tool for the characterization, verification, and validation (QCVV) of quantum processors. Only for a few idealized scenarios, there are analytic results for the optimal measurement set for QST. E.g., in a setting of non-degenerate measurements, an optimal minimal set of measurement operators for QST has eigenbases which are mutually unbiased. However, in other set-ups, dependent on the rank of the projection operators and the size of the quantum system, the optimal choice of measurements for efficient QST needs to be numerically approximated. We have generalized this problem by introducing the framework of <i>customized efficient QST</i>. Here we extend customized QST and look for the optimal measurement set for QST in the case where some of the quantum gates applied in the measurement process are noisy. To achieve this, we use two distinct noise models: first, the depolarizing channel, and second, over- and under-rotation in single-qubit and to two-qubit gates (for further information, please see Methods). We demonstrate the benefit of using entangling gates for the efficient QST measurement schemes for two qubits at realistic noise levels, by comparing the fidelity of reconstruction of our optimized QST measurement set to the state-of-the-art scheme using only product bases.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00181-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5090538","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}

引用次数: 2

Quantum adversarial metric learning model based on triplet loss function 基于三重损失函数的量子对抗度量学习模型

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-27 DOI: 10.1140/epjqt/s40507-023-00182-1

Yan-Yan Hou, Jian Li, Xiu-Bo Chen, Chong-Qiang Ye

{"title":"Quantum adversarial metric learning model based on triplet loss function","authors":"Yan-Yan Hou, Jian Li, Xiu-Bo Chen, Chong-Qiang Ye","doi":"10.1140/epjqt/s40507-023-00182-1","DOIUrl":"10.1140/epjqt/s40507-023-00182-1","url":null,"abstract":"<div><p>Metric learning plays an essential role in image analysis and classification, and it has attracted more and more attention. In this paper, we propose a quantum adversarial metric learning (QAML) model based on the triplet loss function, where samples are embedded into the high-dimensional Hilbert space and the optimal metric is obtained by minimizing the triplet loss function. The QAML model employs entanglement and interference to build superposition states for triplet samples so that only one parameterized quantum circuit is needed to calculate sample distances, which reduces the demand for quantum resources. Considering the QAML model is fragile to adversarial attacks, an adversarial sample generation strategy is designed based on the quantum gradient ascent method, effectively improving the robustness against the functional adversarial attack. Simulation results show that the QAML model can effectively distinguish samples of MNIST and Iris datasets and has higher <i>ϵ</i>-robustness accuracy over the general quantum metric learning. The QAML model is a fundamental research problem of machine learning. As a subroutine of classification and clustering tasks, the QAML model opens an avenue for exploring quantum advantages in machine learning.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00182-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5051299","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}

引用次数: 0

Automated verification of countermeasure against detector-control attack in quantum key distribution 量子密钥分发中对抗探测器控制攻击的自动验证

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-26 DOI: 10.1140/epjqt/s40507-023-00178-x

Polina Acheva, Konstantin Zaitsev, Vladimir Zavodilenko, Anton Losev, Anqi Huang, Vadim Makarov

引用次数: 2

Local oscillator port embedded field enhancement resonator for Rydberg atomic heterodyne technique 用于Rydberg原子外差技术的本振口内嵌场增强谐振器

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-26 DOI: 10.1140/epjqt/s40507-023-00179-w

Kai Yang, Ruiqi Mao, Li He, Jiawei Yao, Jianbing Li, Zhanshan Sun, Yunqi Fu

{"title":"Local oscillator port embedded field enhancement resonator for Rydberg atomic heterodyne technique","authors":"Kai Yang, Ruiqi Mao, Li He, Jiawei Yao, Jianbing Li, Zhanshan Sun, Yunqi Fu","doi":"10.1140/epjqt/s40507-023-00179-w","DOIUrl":"10.1140/epjqt/s40507-023-00179-w","url":null,"abstract":"<div><p>Rydberg atom-based sensors using the atomic heterodyne technique demonstrate prominent performance on sensing sensitivity and thus have significant potential for radar, electronic reconnaissance, and communication applications. Here, we propose a local oscillator (LO) embedded field enhancement resonator to improve the sensitivity and integration of Rydberg atomic heterodyne sensors. In this approach, a vapor cell filled with cesium atoms is placed into the resonance structure for electric (E) field measurements. By integrating parallel-plate waveguide (PPWG) antennas and the resonator, the LO signal can be directly guided to the resonator using coaxial cable instead of the use of external antennas radiating through free space, allowing for a more flexible and practical Rydberg atom-based heterodyne technique. Based on the off-resonant Rydberg atomic heterodyne approach, for a radio frequency (RF) signal at 638 MHz, it is found that the sensitivity is 43 <i>μ</i>V/cm<span>(sqrt{text{Hz}})</span> in the absence of the resonator, while in the presence of our resonator, the sensitivity is down to 854.36 nV/cm<span>(sqrt{text{Hz}})</span>, indicating 50 times or 34 dB improvement capacity of the proposed resonator. This type of enhancement resonator is expected to benefit Rydberg atomic heterodyne applications in practical environments.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00179-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5007985","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}

引用次数: 0

Security and application of semi-quantum key distribution protocol for users with different quantum capabilities 不同量子能力用户的半量子密钥分发协议的安全性与应用

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-20 DOI: 10.1140/epjqt/s40507-023-00180-3

Chong-Qiang Ye, Jian Li, Xiu-Bo Chen, Yanyan Hou, Zhuo Wang

{"title":"Security and application of semi-quantum key distribution protocol for users with different quantum capabilities","authors":"Chong-Qiang Ye, Jian Li, Xiu-Bo Chen, Yanyan Hou, Zhuo Wang","doi":"10.1140/epjqt/s40507-023-00180-3","DOIUrl":"10.1140/epjqt/s40507-023-00180-3","url":null,"abstract":"<div><p>Semi-quantum protocols serve as a bridge between quantum users and “classical” users with limited quantum capabilities, providing support for application scenarios that cannot afford the excessively high cost of quantum resources. In this paper, we present a semi-quantum key distribution (SQKD) protocol based on Bell states and single particles, which is designed for key distribution between different types of users. The protocol enables simultaneous key distribution between quantum and classical users, as well as key establishment between two classical users. The security analysis demonstrates that the protocol can reach the same level of security as the full quantum protocol. Furthermore, we extrapolate the proposed protocol to other semi-quantum protocols, such as semi-quantum key agreement and semi-quantum private comparison protocols. Compared with previous similar ones, our SQKD protocol and its extended versions can fulfill the requirements of their respective counterparts individually. Therefore, our SQKD protocol has the potential for broader applications in practical scenarios.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00180-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4794555","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}

引用次数: 0

Impact of transmitter imbalances on the security of continuous variables quantum key distribution 发送器不平衡对连续变量量子密钥分发安全性的影响

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-14 DOI: 10.1140/epjqt/s40507-023-00176-z

Daniel Pereira, Margarida Almeida, Armando N. Pinto, Nuno A. Silva

{"title":"Impact of transmitter imbalances on the security of continuous variables quantum key distribution","authors":"Daniel Pereira, Margarida Almeida, Armando N. Pinto, Nuno A. Silva","doi":"10.1140/epjqt/s40507-023-00176-z","DOIUrl":"10.1140/epjqt/s40507-023-00176-z","url":null,"abstract":"<div><p>Continuous-variable quantum key distribution (CV-QKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users in a communication network. However, the practical devices used to implement these systems are intrinsically imperfect, and, as a result, open the door to eavesdropper attacks. In this work, we study the impact of transmitter stage imperfections on the performance and security of a Discrete Modulated (DM) CV-QKD system using M-symbol Quadrature Amplitude Modulation (M-QAM) and Amplitude and Phase Shift Keying (M-APSK) coupled with Probabilistic Constellation Shaping (PCS). Assuming two different modulation stage topologies, we first deform the constellations and then evaluate the secure key rate achievable with the deformed constellation. The presented results show that, due to the erroneously estimated channel parameters, non-monitored imbalances greatly reduce the system’s performance, with situations where Bob and Alice estimate that no secure bits can be obtained while the real value of the key rate is still positive. Our results show the importance of monitoring these constellation imbalances and show that the optimal constellation may vary depending on the degree of device imperfection.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00176-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4576121","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}

引用次数: 1