EPJ Quantum Technology最新文献_第2页

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

Dissipative generation of significant amount of photon-phonon asymmetric steering in magnomechanical interfaces 磁力学界面中大量光子-声子不对称转向的耗散产生

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-06-08 DOI: 10.1140/epjqt/s40507-023-00177-y

Tian-Ang Zheng, Ye Zheng, Lei Wang, Chang-Geng Liao

{"title":"Dissipative generation of significant amount of photon-phonon asymmetric steering in magnomechanical interfaces","authors":"Tian-Ang Zheng, Ye Zheng, Lei Wang, Chang-Geng Liao","doi":"10.1140/epjqt/s40507-023-00177-y","DOIUrl":"10.1140/epjqt/s40507-023-00177-y","url":null,"abstract":"<div><p>A theoretical scheme is proposed to generate significant amount of photon-phonon entanglement and asymmetric steering in a cavity magnomechanical system, which is constituted by trapping a yttrium iron garnet sphere in a microwave cavity. By applying a blue-detuned microwave driving field, we obtain an effective Hamiltonian where the magnon mode acting as an engineered resevoir cools the Bogoliubov modes of microwave cavity mode and mechanical mode via a beam-splitter-like interaction. By this means, the microwave cavity mode and mechanical mode can be driven to a two-mode squeezed state in the stationary limit. Particularly, strong two-way and one-way photon-phonon asymmetric quantum steering can be obtained with even equal dissipation. It is widely divergent with the conventional proposal, where additional unbalanced losses or noises should be imposed on the two subsystems. Our finding may be significant to expand our understanding of the essential physics of asymmetric steering and extend the potential application of the cavity spintronics to device-independent quantum key distribution.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00177-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4349125","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

Decoy state semi-quantum key distribution 诱饵态半量子密钥分配

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-05-31 DOI: 10.1140/epjqt/s40507-023-00175-0

Shuang Dong, Shang Mi, Qingcheng Hou, Yutao Huang, Jindong Wang, Yafei Yu, Zhengjun Wei, Zhiming Zhang, Junbin Fang

{"title":"Decoy state semi-quantum key distribution","authors":"Shuang Dong, Shang Mi, Qingcheng Hou, Yutao Huang, Jindong Wang, Yafei Yu, Zhengjun Wei, Zhiming Zhang, Junbin Fang","doi":"10.1140/epjqt/s40507-023-00175-0","DOIUrl":"10.1140/epjqt/s40507-023-00175-0","url":null,"abstract":"<div><p>Semi-quantum key distribution describes a system in which a fully quantum user and classical user perform key distribution. The main advantage of key distribution is its security. Owing to the bottlenecks of existing technology, highly attenuated lasers and threshold detectors are required for semi-quantum key distribution; however, these components make semi-quantum key distribution susceptible to eavesdroppers. Our previous study presented the first semi-quantum key distribution experiment and verified the feasibility of the mirror protocol in 2021. Herein, we first build a semi-quantum key distribution channel model and use Gottesman-Lo-Lütkenhaus-Preskill theory to evaluate its safety performance in the case of a quasi-single photon source. Moreover, we determine that an eavesdropper can steal all information through the photon-number-splitting attack without being detected. Therefore, we add decoy states to the semi-quantum key distribution to estimate the furthest transmission distance and secure bit rate under asymptotic conditions. Semi-quantum key distribution can still be achieved safely with highly attenuated lasers and threshold detectors in 150 km.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00175-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5189761","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

A quantum circuit to generate random numbers within a specific interval 在特定间隔内产生随机数的量子电路

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-05-25 DOI: 10.1140/epjqt/s40507-023-00174-1

Francisco Orts, Ernestas Filatovas, Ester M. Garzón, Gloria Ortega

{"title":"A quantum circuit to generate random numbers within a specific interval","authors":"Francisco Orts, Ernestas Filatovas, Ester M. Garzón, Gloria Ortega","doi":"10.1140/epjqt/s40507-023-00174-1","DOIUrl":"10.1140/epjqt/s40507-023-00174-1","url":null,"abstract":"<div><p>Random numbers are of vital importance in fields such as cyptography and scientific simulations. However, it is well known how difficult it is for classical computers to generate random numbers. This is not the case for quantum computers, which are able to genuinely generate random numbers thanks to the property of superposition and their counter-intuitive concept of measurement. However, despite the simplicity of designing a circuit that generates a random number between 0 and <span>(2^{N}-1)</span> (being <i>N</i> the number of available qubits), designing a quantum circuit to generate a number within a specific interval is far from trivial. This paper proposes a customizable circuit design to generate random numbers. The circuit is non- hardware dependent, it allows fault-tolerance, and it can be used by current quantum devices. Therefore, it is a valuable tool for all those quantum applications and algorithms that need to work with random numbers. Moreover, a comparator circuit has also been designed as part of this work. This comparator is the best currently available in the literature in terms of qubits, T-count, and T-depth. It is therefore a useful tool for any other circuit or algorithm where this operation is needed.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00174-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4979890","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

Ancilla-driven blind quantum computation for clients with different quantum capabilities 具有不同量子能力的客户端的辅助驱动盲量子计算

IF 5.3 2区物理与天体物理

EPJ Quantum Technology Pub Date : 2023-05-23 DOI: 10.1140/epjqt/s40507-023-00173-2

Qunfeng Dai, Junyu Quan, Xiaoping Lou, Qin Li

{"title":"Ancilla-driven blind quantum computation for clients with different quantum capabilities","authors":"Qunfeng Dai, Junyu Quan, Xiaoping Lou, Qin Li","doi":"10.1140/epjqt/s40507-023-00173-2","DOIUrl":"10.1140/epjqt/s40507-023-00173-2","url":null,"abstract":"<div><p>Blind quantum computation (BQC) allows a client with limited quantum power to delegate his quantum computational task to a powerful server and still keep his input, output, and algorithm private. There are mainly two kinds of models about BQC, namely circuit-based and measurement-based models. In addition, a hybrid model called ancilla-driven universal blind quantum computation (ADBQC) was proposed by combining the properties of both circuit-based and measurement-based models, where all unitary operations on the register qubits can be realized with the aid of single ancilla coupled to the register qubits. However, in the ADBQC model, the quantum capability of the client is strictly limited to preparing single qubits. If a client can only perform single-qubit measurements or a few simple quantum gates, he will not be able to perform ADBQC. This paper solves the problem and extends the existing model by proposing two types of ADBQC protocols for clients with different quantum capabilities, such as performing single-qubit measurements or single-qubit gates. Furthermore, in the two proposed ADBQC protocols, clients can detect whether servers are honest or not with a high probability by using corresponding verifiable techniques.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"10 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-023-00173-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5226130","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