Shu-Qian Shen, Xin-Qi Gao, Rui-Qi Zhang, Ming Li, Shao-Ming Fei
{"title":"Implementation of Entanglement Witnesses with Quantum Circuits","authors":"Shu-Qian Shen, Xin-Qi Gao, Rui-Qi Zhang, Ming Li, Shao-Ming Fei","doi":"10.1002/qute.202400272","DOIUrl":"10.1002/qute.202400272","url":null,"abstract":"<p>Entanglement witnesses are economical tools for the experimental detection of quantum entanglement. Quantum algorithms for entanglement detection have recently attracted considerable attention. Based on block encoding techniques and state preparation methods, the implementation of several types of entanglement witnesses using quantum circuits without quantum state tomography is proposed. Further, explicit quantum circuits for the block encoding of some special matrices are presented.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262890","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":"Enhancing the Sensitivity of Quantum Fiber-Optical Gyroscope via a Non-Gaussian-State Probe","authors":"Wen-Xun Zhang, Rui Zhang, Yunlan Zuo, Le-Man Kuang","doi":"10.1002/qute.202400270","DOIUrl":"10.1002/qute.202400270","url":null,"abstract":"<p>A theoretical scheme to enhance the sensitivity of a quantum fiber-optical gyroscope (QFOG) via a non-Gaussian-state probe based on quadrature measurements of the optical field is proposed. The non-Gaussian-state probe utilizes the product state comprising a photon-added coherent state (PACS) with photon excitations and a coherent state (CS). The sensitivity of the QFOG is studied and it is found that it can be significantly enhanced through increasing the photon excitations in the PACS probe. The influence of photon loss on the performance of QFOG is investigated and it is demonstrated that the PACS probe exhibits robust resistance to photon loss. Furthermore, the performance of the QFOG using the PACS probe against two Gaussian-state probes: the CS probe and the squeezed state (SS) probe is compared and it is indicated that the PACS probe offers a significant advantage in terms of sensitivity, regardless of photon loss, under the constraint condition of the same total number of input photons. Particularly, it is found that the sensitivity of the PACS probe can be three orders of magnitude higher than that of two Gaussian-state probes for certain values of the measured parameter. The capabilities of the non-Gaussian state probe in enhancing the sensitivity and resisting photon loss can have a wide-ranging impact on future high-performance QFOGs.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262889","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: Superconducting Diode Effect in a Constricted Nanowire (Adv. Quantum Technol. 9/2024)","authors":"Xiaofu Zhang, Qingchang Huan, Ruoyan Ma, Xingyu Zhang, Jia Huang, Xiaoyu Liu, Wei Peng, Hao Li, Zhen Wang, Xiaoming Xie, Lixing You","doi":"10.1002/qute.202470023","DOIUrl":"https://doi.org/10.1002/qute.202470023","url":null,"abstract":"<p>Superconducting diodes with nonreciprocal transport effect enable constructing novel logic devices, thereby laying the cornerstone of contemporary integrated circuits technology beyond Josephson junction-based circuits. Xiaofu Zhang, Lixing You, and co-workers designed and fabricated novel superconducting diodes based on the minimal superconducting electrical component – the superconducting nanowire –, which can rectify both square-wave and sine-wave signals without distortion (see article number 2300378). The superconducting nanowire diodes are irrespective of specific superconducting materials, and therefore promising for constructing low-dissipation superconducting integrated circuits for novel computation architectures.\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":"7 9","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202470023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170095","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":"Inside Front Cover: Compact and Stable Diamond Quantum Sensors for Wide Applications (Adv. Quantum Technol. 9/2024)","authors":"Yuta Kainuma, Yuji Hatano, Takayuki Shibata, Naota Sekiguchi, Akimichi Nakazono, Hiromitsu Kato, Shinobu Onoda, Takeshi Ohshima, Mutsuko Hatano, Takayuki Iwasaki","doi":"10.1002/qute.202470024","DOIUrl":"https://doi.org/10.1002/qute.202470024","url":null,"abstract":"<p>A diamond quantum sensor, based on an ensemble of nitrogen-vacancy (NV) centers in diamond, is depicted being held by the author's hand. This sensor module is compact, highly magnetically sensitive, and stable. It was achieved by mounting a <sup>12</sup>C-enriched chemical vapor deposition diamond, optics for high collection efficiency of NV fluorescence, and a balancing circuit to cancel out laser noise in the sensor module. This compact module is expected to be versatile across a broad spectrum of applications. For further information on the device and its applications, see article number 2300456 by Yuta Kainuma, Takayuki Iwasaki, and co-workers.\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":"7 9","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202470024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170162","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}
Lü Xiang, He Wang, Zi-Meng Li, Zhu-Cheng Zhang, Yi-Ping Wang
{"title":"Back Cover: Triggering and Modulation of Quantum Magnon-Photon Hall Insulator in a 1D Cavity Magnonics Lattice (Adv. Quantum Technol. 9/2024)","authors":"Lü Xiang, He Wang, Zi-Meng Li, Zhu-Cheng Zhang, Yi-Ping Wang","doi":"10.1002/qute.202470026","DOIUrl":"https://doi.org/10.1002/qute.202470026","url":null,"abstract":"<p>In article number 2400111, Zhu-Cheng Zhang, Yi-Ping Wang, and co-workers propose a scheme for implementing a one-dimensional cavity magnonics lattice that exhibits quantum magnon–photon Hall insulator behaviors. By adjusting corresponding parameters, different energy spectrum structures can be triggered, and the flipping of edge states can be observed, enabling multi-channel topological quantum state transmission.\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":"7 9","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202470026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170163","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":"High-Dimensional Photonic Quantum Computing with a Measurement-Free Auxiliary System","authors":"Xue-Mei Ren, Fang-Fang Du","doi":"10.1002/qute.202400208","DOIUrl":"10.1002/qute.202400208","url":null,"abstract":"<p>Enhancing the capabilities of quantum computing relies heavily on harnessing the power of qudit-based high-dimensional quantum gates. In the study, single-qudit 4D <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$ X$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>X</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <annotation>$ X^{2}$</annotation>\u0000 </semantics></math>, and <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>X</mi>\u0000 <mo>†</mo>\u0000 </msup>\u0000 <annotation>$ X^{dagger }$</annotation>\u0000 </semantics></math> gates tailored for a two-photon system in polarization states are presented. Furthermore, a two-qudit <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>4</mn>\u0000 <mo>×</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 <annotation>$4times 4$</annotation>\u0000 </semantics></math>-dimensional controlled-not (CNOT) gate designed for a four-photon system is introduced. These high-dimensional gates can offer versatile and straightforward optical implementations, ensuring them to fulfill in a deterministic way. To facilitate these processes, an auxiliary system in the form of a <span></span><math>\u0000 <semantics>\u0000 <mi>Λ</mi>\u0000 <annotation>$Lambda$</annotation>\u0000 </semantics></math>-type atom residing in a cavity is employed. Remarkably, the auxiliary system retains its original state after the operation process ends, so it is not required to measure and plays a pivotal role in promoting effective interactions among distinct photons in its extended coherence time. Importantly, the in-depth analysis of the fidelities and efficiencies of these quantum gates showcase remarkable outcomes, affirming the superiority of the proposed protocols. Therefore, these high-dimensional gates not only amplify quantum parallelism, but also bolster the speed of quantum computations, fortify resilience against errors, and foster scalability for executing intricate quantum operations.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 11","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218903","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}
Rafael I. Nepomechie, Francesco Ravanini, David Raveh
{"title":"Spin-\u0000 \u0000 s\u0000 $s$\u0000 Dicke States and Their Preparation","authors":"Rafael I. Nepomechie, Francesco Ravanini, David Raveh","doi":"10.1002/qute.202400057","DOIUrl":"10.1002/qute.202400057","url":null,"abstract":"<p>The notion of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>s</mi>\u0000 <mi>u</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$su(2)$</annotation>\u0000 </semantics></math> spin-<span></span><math>\u0000 <semantics>\u0000 <mi>s</mi>\u0000 <annotation>$s$</annotation>\u0000 </semantics></math> Dicke states is introduced, which are higher-spin generalizations of usual (spin-1/2) Dicke states. These multi-qudit states can be expressed as superpositions of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>s</mi>\u0000 <mi>u</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mi>s</mi>\u0000 <mo>+</mo>\u0000 <mn>1</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$su(2s+1)$</annotation>\u0000 </semantics></math> qudit Dicke states. They satisfy a recursion formula, which is used to formulate an efficient quantum circuit for their preparation, whose size scales as <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>s</mi>\u0000 <mi>k</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mi>s</mi>\u0000 <mi>n</mi>\u0000 <mo>−</mo>\u0000 <mi>k</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$sk(2sn-k)$</annotation>\u0000 </semantics></math>, where <span></span><math>\u0000 <semantics>\u0000 <mi>n</mi>\u0000 <annotation>$n$</annotation>\u0000 </semantics></math> is the number of qudits and <span></span><math>\u0000 <semantics>\u0000 <mi>k</mi>\u0000 <annotation>$k$</annotation>\u0000 </semantics></math> is the number of times the total spin-lowering operator is applied to the highest-weight state. The algorithm is deterministic and does not require ancillary qudits.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218904","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}