Advanced quantum technologies最新文献

{"title":"pH Controlled Twist-Angle Dependent Interfacial Quantum Tunneling in Multilayer Molecular Moiré Superlattices of p-Phenylenediamine","authors":"Ujjala Dey,&nbsp;Arun Chattopadhyay","doi":"10.1002/qute.202400569","DOIUrl":"10.1002/qute.202400569","url":null,"abstract":"<p>Molecule-based electronic circuits and device components may bring novel aspects in their functioning based on quantum phenomena that may not be attainable using conventional architecture. In order to implement such concepts development of well-defined assemblies that enable energy transfer, mass, and charge transports across several length scales is necessary. Herein it is reported that multilayer molecular moiré superlattices may provide an initial direction for attaining the abovementioned objectives. For example, multilayered 2D moiré superlattices of p-phenylenediamine showed easily identifiable twist angle-dependent electrical conductivity at each interface, as measured for the nanosheet using conductive atomic force microscopy. The absence of water molecules at the interfaces, as compared to the layered water molecules in the lattices, lowered the electron tunneling barrier and thus, increased the conductivity. Importantly, protonation and deprotonation of the superlattices in the dispersion resulted in high interfacial currents with about three orders of magnitude increase for the former. These results are further explained by density of states calculations along with carrier density and simulated scanning tunneling microscopy (STM) plots.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057989","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":"Quantum Signatures of Chaos in Anisotropic Quantum Rabi Model","authors":"Shangyun Wang,&nbsp;Songbai Chen,&nbsp;Jiliang Jing,&nbsp;Jieci Wang,&nbsp;Heng Fan","doi":"10.1002/qute.202400460","DOIUrl":"10.1002/qute.202400460","url":null,"abstract":"<p>Quantum chaos is an intriguing topic and has attracted a great deal of interests in quantum mechanics and black hole physics. Recently, the exponential growth of out-of-time-ordered correlator (OTOC) has been proposed to diagnose quantum chaos and verify the correspondence principle. Here, good correspondence is found between the linear entanglement entropy and the semiclassical phase space structures in the anisotropic quantum Rabi model. The Loschmidt echo in the chaotic sea decays more faster than that in the stable island. However, the OTOCs grow exponentially at early times for the initial states centered both in the chaotic and stable regions. The exponential growth of the OTOC is attributed to quantum collapse that provides a novel mechanism of yielding exponential growth of the OTOC in quantum systems. Moreover, the quantum collapse effect is more obvious for the initial states centered in the chaotic one. The results show that in the anisotropic quantum Rabi model, the linear entanglement entropy, and Loschmidt echo are more effective than OTOC for diagnosing quantum chaotic signals.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 7","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635285","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":"Differential Frequency Comparison of Conditionally and Unconditionally Spin-Squeezed States of an Optical Lattice Clock","authors":"Deshui Yu,&nbsp;Xiaobo Xue,&nbsp;Jia Zhang,&nbsp;Shougang Zhang,&nbsp;Jingbiao Chen","doi":"10.1002/qute.202400491","DOIUrl":"10.1002/qute.202400491","url":null,"abstract":"<p>Optical lattice clocks are the world's most accurate and stable timepieces. Thus far, the differential clock comparison has reached a stability limited by the quantum projection noise of uncorrelated atoms. Overcoming this limit relies on using spin squeezing, where quantum fluctuations of the collective spin undergo a strong suppression in one direction while being enhanced in the conjugation direction. The recent differential comparison of spin-squeezed clocks mainly employs multiple atomic clouds or sub-ensembles within one cloud, complicating the clock operation. Here, it is numerically investigated the differential comparison of conditionally and unconditionally spin-squeezed states of one lattice-trapped cloud of neutral <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow></mrow>\u0000 <mn>171</mn>\u0000 </msup>\u0000 <mtext>Yb</mtext>\u0000 </mrow>\u0000 <annotation>$^{171}text{Yb}$</annotation>\u0000 </semantics></math> atoms. The simulation results in a comparison stability of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>3.5</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>17</mn>\u0000 </mrow>\u0000 </msup>\u0000 <mo>/</mo>\u0000 <msqrt>\u0000 <mi>τ</mi>\u0000 </msqrt>\u0000 </mrow>\u0000 <annotation>$3.5times 10^{-17}/sqrt {tau }$</annotation>\u0000 </semantics></math> at the averaging time <span></span><math>\u0000 <semantics>\u0000 <mi>τ</mi>\u0000 <annotation>$tau$</annotation>\u0000 </semantics></math> for <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <annotation>$10^{2}$</annotation>\u0000 </semantics></math> atoms. The metrological gain reaches <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>4.9</mn>\u0000 </mrow>\u0000 <annotation>$-4.9$</annotation>\u0000 </semantics></math> dB, primarily limited by the decoherence induced by quantum jumps of intracavity probe photons during quantum non-demolition measurements. Besides the quantum precision enhancement, our scheme paves the way to using one spin squeezing protocol to appraise the other.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 8","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832937","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":"Multi-Photon Fock State Generation via Selective Single Photon Subtraction in a Cascaded Waveguide QED System","authors":"Abdolreza Pasharavesh,&nbsp;Michal Bajcsy","doi":"10.1002/qute.202400616","DOIUrl":"10.1002/qute.202400616","url":null,"abstract":"<p>This work presents a deterministic photon subtraction scheme that selectively extracts photons from an input light stream based on their arrival time sequence. The scheme exploits the temporal entanglement generated during single-photon Raman interaction in a chiral waveguide coupled to a cascade of Λ-type atoms. It is demonstrated that this photon subtractor enables the generation of high-fidelity and modal purity multi-photon Fock states. Using a variational approach, the modal structure of the output light is identified, based on a non-orthogonal basis formed through post-selection of the output pulses. Within an input-output network framework, numerical simulations are performed to calculate the quantum state of the output light. Additionally, the use of the generated Fock-state pulses in optical interferometry is investigated, demonstrating their potential for quantum metrology applications at the Heisenberg limit.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400616","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058098","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":"Improved Grey Wolf-Differential Evolution Algorithm for UAV OAM-MDI-QKD Parameter Optimization","authors":"Dan Wu,&nbsp;Jiahao Li,&nbsp;Xile Cui,&nbsp;Zhifeng Deng,&nbsp;Jie Tang,&nbsp;Yuexiang Cao,&nbsp;Ying Liu,&nbsp;Haoran Hu,&nbsp;Ya Wang,&nbsp;XingYu Wang,&nbsp;Huicun Yu,&nbsp;Jiahua Wei,&nbsp;Huazhi Lun,&nbsp;Lei Shi","doi":"10.1002/qute.202400423","DOIUrl":"10.1002/qute.202400423","url":null,"abstract":"<p>The integration of unconditional security of quantum key distribution (QKD) with the flexibility of unmanned aerial vehicles (UAVs) presents significant potential for the deployment of comprehensive quantum networks. However, imperfect components of practical QKD systems offer avenues for eavesdropping, while the limited payload capacity and vibrations of UAVs present substantial challenges. This paper introduces an orbital angular momentum (OAM) encoding strategy combined with decoy-state and the measurement-device-independent QKD (MDI-QKD) protocol to address security issues and reference frame misalignment in UAV-based QKD systems. Nevertheless, the communication performance of the OAM-MDI-QKD system is significantly affected by complex environmental challenges in the airborne channel. To improve the degraded communication performance in airborne platforms, an enhanced grey wolf optimization-differential evolution (GWO-DE) algorithm is developed, utilizing chaotic mapping and a nonlinear decay factor to strengthen global search and convergence capabilities, which effectively addresses the search limitations of local search algorithms (LSA) when dealing with high-dimensional objective functions. Simulation results demonstrate that the GWO-DE algorithm outperforms other traditional optimization algorithms in terms of optimization precision and transmission distance enhancement, with computational speed meeting system requirements.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 7","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635302","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":"Improving User Privacy in Practical Quantum Private Query with Group Honesty Checking","authors":"Chun-Yan Wei,&nbsp;Qing-Le Wang,&nbsp;Xiao-Qiu Cai,&nbsp;Tian-Yin Wang","doi":"10.1002/qute.202400429","DOIUrl":"10.1002/qute.202400429","url":null,"abstract":"&lt;p&gt;Current cheat-sensitive security level of user privacy in quantum private query (QPQ) is far from meeting its ideal requirement. Dishonest database trying to elicit user privacy can only be (delayedly) detected after the finish of the protocol with merely a nonzero probability. Worse yet, no estimation of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mi&gt;u&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$p_{succ}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;(i.e., the success probability of dishonest database's cheating) has been given till now. Such estimation is quite necessary because a significant &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mi&gt;u&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$p_{succ}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; means frangible user privacy especially in the cheat-sensitive security model. Here, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mi&gt;u&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$p_{succ}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of the first and best-known quantum-key-distribution (QKD)-based QPQ protocol proposed by Jakobi et al. is estimated, which shows that dishonest database can elicit user privacy with significant probability (e.g., as high as 42.8% for database size &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;N&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;10000&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$N=10000$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) while such cheating can only be (delayedly) detected with probability 50 %. Common strategy to improve user privacy, i.e., adding honesty checking to detect malicious database may hurt the privacy of the other party, i.e. database security. To solve this problem, a new group honesty checking is proposed, which will not hurt database security and can reduce $ &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mi&gt;u&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$p_{succ}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; to a very small value (e.g. 0.26% for database size 10000), thus a","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 3","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622661","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":"Back Cover: Direct-Laser-Written Polymer Nanowire Waveguides for Broadband Single Photon Collection from Epitaxial Quantum Dots into a Gaussian-like Mode (Adv. Quantum Technol. 2/2025)","authors":"Edgar F. Perez,&nbsp;Cori Haws,&nbsp;Marcelo Davanco,&nbsp;Jindong Song,&nbsp;Luca Sapienza,&nbsp;Kartik Srinivasan","doi":"10.1002/qute.202570004","DOIUrl":"10.1002/qute.202570004","url":null,"abstract":"<p>In article number 2300149, Edgar F. Perez, Kartik Srinivasan, and co-workers study the use of polymer nanowire waveguides fabricated by direct laser writing lithography for the extraction of single quantum dot emission into a Gaussian-like far-field optical mode. The use of such polymer nanowires on both bulk quantum dot material and on underlying nanofabricated devices is considered and an enhanced extraction efficiency relative to measurements without the nanowires is shown. Moreover, the nanowires can be fabricated with high yield.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 2","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202570004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389407","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":"Recent Advances in Photonic Quantum Technologies","authors":"Mohamed Benyoucef","doi":"10.1002/qute.202400628","DOIUrl":"10.1002/qute.202400628","url":null,"abstract":"","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 2","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389408","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":"Front Cover: Spatial Distribution Control of Room-Temperature Single Photon Emitters in the Telecom Range from GaN Thin Films Grown on Patterned Sapphire Substrates (Adv. Quantum Technol. 2/2025)","authors":"Hyemin Kim,&nbsp;Yong-Ho Song,&nbsp;Young-Ho Ko,&nbsp;Yong-Hoon Cho","doi":"10.1002/qute.202570003","DOIUrl":"10.1002/qute.202570003","url":null,"abstract":"<p>In article number 2400177, Yong-Hoon Cho and co-workers controlled spatial distribution of room-temperature, telecom-wavelength emitting single-photon emitters (bright red colours) based on defects in GaN thin film grown on patterned sapphire substrates with varying pattern sizes and dimensions. This approach effectively controls the position of emitters between patterns and enhances the photon extraction efficiency via pattern size optimization.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 2","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202570003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389406","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":"Issue Information (Adv. Quantum Technol. 2/2025)","authors":"","doi":"10.1002/qute.202570005","DOIUrl":"10.1002/qute.202570005","url":null,"abstract":"","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 2","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202570005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389405","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}