Advanced quantum technologies最新文献

{"title":"Mid-Infrared Sensing Using a Hollow–Core Fiber in a Nonlinear Interferometer","authors":"Thomas Produit,&nbsp;Tanmoy Chakraborty,&nbsp;Ang Deng,&nbsp;Leonid Krivitsky,&nbsp;Wonkeun Chang,&nbsp;Anna V. Paterova","doi":"10.1002/qute.202400397","DOIUrl":"https://doi.org/10.1002/qute.202400397","url":null,"abstract":"<p>Increasing the interaction path length is a well-known method for enhancing the sensitivity of the optical detection system. Hollow–core fibers (HCFs) represent a viable alternative to the traditional multi-path cells offering low optical losses and strong confinement of the optical field. Here, the incorporation of an Antiresonant Hollow–core Fiber (AR-HCF) section into a nonlinear interferometer, where the AR-HCF section serves as a gas-sensing cell operating in the IR range is presented. By exploiting the effect of nonlinear interference, the detection is brought into the more operation-friendly visible range. The detection of methane (CH₄) gas at mid-IR wavelengths within a half-meter section of AR-HCF, with an estimated concentration accuracy of 200 ppm·m is demonstrated. These results represent the combination of two research fields within a single instrument and pave the way for further advancement of quantum-inspired gas sensing techniques.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 4","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Witnessing Entanglement and Quantum Correlations in Condensed Matter: A Review","authors":"Pontus Laurell,&nbsp;Allen Scheie,&nbsp;Elbio Dagotto,&nbsp;D. Alan Tennant","doi":"10.1002/qute.202400196","DOIUrl":"https://doi.org/10.1002/qute.202400196","url":null,"abstract":"<p>The detection and certification of entanglement and quantum correlations in materials is of fundamental and far-reaching importance, and has seen significant recent progress. It impacts both the understanding of the basic science of quantum many-body phenomena as well as the identification of systems suitable for novel technologies. Frameworks suitable to condensed matter that connect measurements to entanglement and coherence have been developed in the context of quantum information theory. These take the form of entanglement witnesses and quantum correlation measures.</p><p>The underlying theory of these quantities, their relation to condensed matter experimental techniques, and their application to real materials are comprehensively reviewed. In addition, their usage in, e.g., protocols, the relative advantages and disadvantages of witnesses and measures, and future prospects in, e.g., correlated electrons, entanglement dynamics, and entangled spectroscopic probes, are presented. Consideration is given to the interdisciplinary nature of this emerging research and substantial ongoing progress by providing an accessible and practical treatment from fundamentals to application. Particular emphasis is placed on quantities accessible to collective measurements, including by susceptibility and spectroscopic techniques. This includes the magnetic susceptibility witness, one-tangle, concurrence and two-tangle, two-site quantum discord, and quantum coherence measures such as the quantum Fisher information.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Epitaxial Interfaces for Topological Insulator — Superconductor Hybrid Devices with Al Electrodes","authors":"Abdur Rehman Jalil,&nbsp;Tobias W. Schmitt,&nbsp;Philipp Rüßmann,&nbsp;Xian-Kui Wei,&nbsp;Benedikt Frohn,&nbsp;Michael Schleenvoigt,&nbsp;Wilhelm Wittl,&nbsp;Xiao Hou,&nbsp;Anne Schmidt,&nbsp;Kaycee Underwood,&nbsp;Gustav Bihlmayer,&nbsp;Martina Luysberg,&nbsp;Joachim Mayer,&nbsp;Stefan Blügel,&nbsp;Detlev Grützmacher,&nbsp;Peter Schüffelgen","doi":"10.1002/qute.202400343","DOIUrl":"https://doi.org/10.1002/qute.202400343","url":null,"abstract":"<p>Proximity-induced superconductivity in hybrid devices of topological insulators and superconductors offers a promising platform for the pursuit of elusive topological superconductivity and its anticipated applications, such as fault-tolerant quantum computing. To study and harness such hybrid devices, a key challenge is the realization of highly functional material interfaces with a suitable superconductor featuring 2<span></span><math>\u0000 <semantics>\u0000 <mi>e</mi>\u0000 <annotation>$e$</annotation>\u0000 </semantics></math>-periodic parity-conserving transport to ensure a superconducting hard-gap free of unpaired electrons, which is important for Majorana physics. A superconductor well-known for this characteristic is Al, however, its direct integration into devices based on tetradymite topological insulators has so far been found to yield non-transparent interfaces. By focusing on Bi₂Te₃-Al heterostructures, this study identifies detrimental interdiffusion processes at the interface through atomically resolved structural and chemical analysis, and showcases their mitigation by leveraging different interlayers – namely Nb, Ti, Pd, and Pt – between Bi₂Te₃ and Al. Through structural transformation of the interlayer materials (X) into their respective tellurides (XTe₂) atomically-sharp epitaxial interfaces are engineered and further characterized in low-temperature transport experiments on Al-X-Bi₂Te₃-X-Al Josephson junctions and in complementary density functional theory calculations. By demonstrating functional interfaces between Bi₂Te₃ and Al, this work provides key insights and paves the way for the next generation of sophisticated topological devices.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400343","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discrete and Parallel Frequency-Bin Entanglement Generation from Quantum Frequency Comb","authors":"Chi Lu,&nbsp;Xiaoyu Wu,&nbsp;Wenjun Wen,&nbsp;Xiao-song Ma","doi":"10.1002/qute.202400229","DOIUrl":"https://doi.org/10.1002/qute.202400229","url":null,"abstract":"<p>Photons’ frequency degree of freedom is promising to realize large-scale quantum information processing. Quantum frequency combs (QFCs) generated in integrated nonlinear microresonators can produce multiple frequency modes with narrow linewidth. Here, polarization-entangled QFCs are utilized to generate discrete frequency-bin entangled states. Fourteen pairs of polarization-entangled photons with different frequencies are simultaneously transformed into frequency-bin entangled states. The characteristic of frequency-bin entanglement is demonstrated by Hong-Ou-Mandel interference, which can be performed with single or multiple frequency pairs in parallel. This work paves the way for harnessing large-scale frequency-bin entanglement and converting between different degrees of freedom in quantum information processing.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wavelength Stabilization of Entangled Biphotons Using Dynamic Temperature Compensation for Quantum Interference Applications","authors":"Yuting Liu,&nbsp;Huibo Hong,&nbsp;Xiao Xiang,&nbsp;Runai Quan,&nbsp;Xinghua Li,&nbsp;Tao Liu,&nbsp;Mingtao Cao,&nbsp;Shougang Zhang,&nbsp;Ruifang Dong","doi":"10.1002/qute.202400305","DOIUrl":"https://doi.org/10.1002/qute.202400305","url":null,"abstract":"<p>In this paper, a dynamic temperature compensation method is presented to stabilize the wavelength of the entangled biphoton source, which is generated on spontaneous parametric down-conversion from a magnesium oxide doped periodically poled lithium niobate waveguide. Utilizing the dispersive Fourier transformation technique, the photon wavelength variation is monitored in case of conventional static temperature control, revealing a long-term wavelength drift up to 556.8 pm over a 14-h measurement period. A Hong-Ou-Mandel (HOM) interferometer is constructed to assess the impact on quantum applications, showing a decrease in visibility from 95.5% to 69.4%. To address this issue, a digital proportional-integral-differential algorithm is implemented to dynamically compensate the working temperature variation of the waveguide, thereby instantly stabilizing the wavelength to a peak-to-peak fluctuation of +138.05 pm/-127.61 pm with the standard deviation being 30.49 pm. The wavelength stability shows more than a hundredfold enhancement in terms of Allan deviation, reaching <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>1.67</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>7</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$1.67 times {{10}^{ - 7}}$</annotation>\u0000 </semantics></math> at an averaging time of 10000 s. With the dynamic control in operation, the HOM interference visibility turns to stable at 96.1% ± 0.6%. The method provides a simple and accessible solution for precisely controlling and stabilizing the wavelength of entangled biphotons, thus improving performance in various quantum information processing applications.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to Topological Properties of a Non-Hermitian Quasi-1D Chain with a Flat Band","authors":"","doi":"10.1002/qute.202400348","DOIUrl":"https://doi.org/10.1002/qute.202400348","url":null,"abstract":"<p>C. Martínez-Strasser, M. A. J. Herrera, A. García-Etxarri, G. Palumbo, F. K. Kunst, D. Bercioux, Topological Properties of a Non-Hermitian Quasi-1D Chain with a Flat Band. <i>Adv Quantum Technol</i>. <b>2024</b>, <i>7</i>, 2300225.</p><p>In this correction to the article titled “Topological Properties of a Non-Hermitian Quasi-1D Chain with a Flat Band” we show that the previously claimed non-Hermitian skin effect found in the non-Hermitian diamond chain in configuration B (DCB) is mistaken. The observed accumulation of the eigenstates towards the edges in the representation used in Figure 5 results from an incorrect selection of the basis for the flat band eigenstates in the <i>Wolfram Language</i> (WL).</p><p>In general, states in the flat bands are defined as a linear combination of compact localized states (CLSs). However, the WL is unable to determine this basis. As a result, summing the squared amplitudes on each site leads to an accumulation that appears to increase in weight towards the boundaries (see Figure A(a)). Whereas a correct CLS base does not induce this accumulation - see Figure A(b).</p><p>As a result, Figure 5 and Figure 9 are incorrect. Replacement figures are shown in Figures B and D, respectively, below.</p><p>Additionally, Figure D shows the correct representation of the sum of amplitudes at each site of the rotated DCB model presenting real non-reciprocal couplings (refer to Figure 8b in the article). In this model, the right and left eigenvectors are identical. Notably, this model does not exhibit the non-Hermitian skin effect, neither on the sites producing the flat band nor on the Hermitian SSH chain coupled in a non-Hermitian fashion to the flat band sites (see Figure E).</p><p>The authors acknowledge useful discussions with Julius Gohsrich for giving insight to this matter.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400348","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Molecules as Building Blocks for Quantum Technologies","authors":"Eufemio Moreno-Pineda,&nbsp;Wolfgang Wernsdorfer","doi":"10.1002/qute.202300367","DOIUrl":"https://doi.org/10.1002/qute.202300367","url":null,"abstract":"<p>Since the initial observation of quantum effects, scientists have worked diligently to understand and harness their potential. Thanks to many pioneers, a level where quantum effects can be exploited is reached. Numerous cutting-edge technologies, such as quantum sensing and quantum computing, are proposed. A common trait in all technologies is the need to manipulate and read out their states; therefore, the quantum characteristics of the building blocks must adhere to strict guidelines. Magnetic Molecules (MMs) are promising candidates. They can be obtained indistinguishably, and the control over their structural and electronic properties, makes them appealing to act as quantum bits or “qubits”. MMs can be connected to other units while preserving their coherence properties, enabling the implementation of quantum gates. Furthermore, the low-lying energy levels can be exploited as qudits, which can exist in more than 2 states simultaneously (d &gt; 2), allowing them to hold more information efficiently. The larger electronic/nuclear space in qudits can decrease the number of physical units and enhance computational efficiency, reducing error and making them promise for complex problem-solving. In this perspective article, the physical characteristics of MMs and key achievements that position them as promising candidates for quantum technologies, are described.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 2","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202300367","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Quantum Entanglement Detection of General Two Qubits Systems Based on Modified CNN-BiLSTM Model","authors":"Qian Sun,&nbsp;Zhichuan Liao,&nbsp;Nan Jiang","doi":"10.1002/qute.202400373","DOIUrl":"https://doi.org/10.1002/qute.202400373","url":null,"abstract":"<p>Entanglement is a key element in quantum information processing. The detection of entanglement is crucial in many long-range quantum information tasks, including secure communication and fundamental tests of quantum physics, but it is also highly resource-intensive. Even for simple 2-qubits systems, satisfactory detection is challenging. In this work, a modified entanglement detection model combining a convolutional neural network (CNN) and a bidirectional long short-term memory network (BiLSTM) is proposed. It shows that the proposed model can effectively extract the deep features and correlations, enabling accurate classification of simple quantum states, even with only a few tens of training samples. When trained with a large number of highly random samples, the model exhibits outstanding fitting capability, resulting in the reliable classification of nearly all common 2-qubits systems. Furthermore, the model exhibits exceptional adaptability and significant application potential in higher-dimensional systems.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mem-Transistor-Based Gaussian Error–Generating Hardware for Post-Quantum Cryptography Applications","authors":"Moon-Seok Kim,&nbsp;Shania Rehman,&nbsp;Muhammad Farooq Khan,&nbsp;Sungho Kim","doi":"10.1002/qute.202400394","DOIUrl":"https://doi.org/10.1002/qute.202400394","url":null,"abstract":"<p>Quantum computing can potentially hack the information encrypted by traditional cryptographic systems, leading to the development of post-quantum cryptography (PQC) to counteract this threat. The key principle behind PQC is the “learning with errors” problem, where intentional errors make encrypted information unpredictable. Intentional errors refer to Gaussian distributed data. However, implementing Gaussian distributed errors is challenging owing to computational and memory overhead. Therefore, this study proposes a Gaussian error sampler that employs the intrinsic Gaussian properties of nanometer-scale semiconductor devices. The proposed Gaussian error sampler significantly reduces computational and memory overhead. This work comprehensively evaluates the effectiveness of the proposed device by conducting statistical normality tests and generating quantile–quantile plots. The optimal programming voltage is identified to be −5.25 V, and the experimental results confirmed the Gaussian distribution of error data generated by the proposed module, aligning closely with software-generated Gaussian distributions and distinct from uniform random distributions.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400394","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sideband-Selective Single-Photon Blockade in Floquet-Modulated Jaynes–Cummings System","authors":"Shiyan Li,&nbsp;Nan Wang,&nbsp;Ai-Dong Zhu","doi":"10.1002/qute.202400374","DOIUrl":"https://doi.org/10.1002/qute.202400374","url":null,"abstract":"<p>A circuit quantum electrodynamics (QED) scheme is proposed for generating an on-demand single-photon source with full external engineering in a Floquet-modulated Jaynes–Cummings (JC) system. The photon blockade effect can be induced across multiple Floquet sidebands, enabling the selective generation of a bright single-photon beam at a specific sideband frequency by adjusting the external driving field of the qubit, without requiring modifications to the circuit components. This is of significance for practical applications of integrated micro-nano single quantum devices within a quantum information network.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}