Advanced quantum technologies最新文献

{"title":"Non-Markovian Dynamics in Fiber Delay-Line Buffers","authors":"Kim Fook Lee,&nbsp;Prem Kumar","doi":"10.1002/qute.202400533","DOIUrl":"10.1002/qute.202400533","url":null,"abstract":"<p>The non-Markovian effect is studied on a two-photon polarization entangled state, in which one photon from the pair is stored in a fiber delay-line buffer. A model of a photonic qubit coupled to fiber birefringence and a fiber reservoir representing the environment is proposed. Analytically, a non-Markovian probability function is derived for the buffered photon and its paired photon. To verify the probability function, full quantum state tomography of the photon pairs is performed. The probability function fits well with the experimental data and physical values. These results indicate that the quantum system operates slightly above the threshold for a non-Markovian transition. We observe a unique polarization dynamic of the buffered photon. Measures of quantum mutual information are further exploited to study the quantumness of the photon pairs. Werner's well-known separability criterion occurs at a buffer time of about 0.9 ms. These results imply that quantum discord can surpass Werner's criterion, and hence, quantum bi-partite correlation can exist for buffer times greater than 0.9 ms.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 8","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400533","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832968","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":"Enhancement of Sensitivity Near Exceptional Points in Dissipative Qubit-Resonator Systems","authors":"Pei-Rong Han,&nbsp;Fan Wu,&nbsp;Xin-Jie Huang,&nbsp;Huai-Zhi Wu,&nbsp;Chang-Ling Zou,&nbsp;Wei Yi,&nbsp;Mengzhen Zhang,&nbsp;Hekang Li,&nbsp;Kai Xu,&nbsp;Dongning Zheng,&nbsp;Heng Fan,&nbsp;Jianming Wen,&nbsp;Zhen-Biao Yang,&nbsp;Shi-Biao Zheng","doi":"10.1002/qute.202400446","DOIUrl":"10.1002/qute.202400446","url":null,"abstract":"<p>Dissipation usually plays a negative role in quantum metrological technologies, which aim to improve measurement precision by leveraging quantum effects that are vulnerable to environment-induced decoherence. Recently, it has been demonstrated that dissipation can actually be used as a favorable resource for enhancing the susceptibility of signal detection. However, demonstrations of such enhancement for detecting physical quantities in open quantum systems are still lacking. Here a protocol is proposed and demonstrated for realizing such non-Hermitian quantum sensors for probing the coupling between a qubit and a resonator subjecting to energy dissipations. The excitation-number conversion associated with the no-jump evolution trajectory enables removal of the noisy outcomes with quantum jumps, implementing the exceptional point (EP), where the Rabi splitting exhibits a divergent behavior in response to a tiny variation of the effective coupling. The sensitivity enhancement near the EP is confirmed by both theoretical calculation and experimental measurement.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 7","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635571","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":"Disentanglement–Induced Bistability in a Magnetic Resonator","authors":"Eyal Buks","doi":"10.1002/qute.202400587","DOIUrl":"10.1002/qute.202400587","url":null,"abstract":"<p>Multi–stability in the response of a ferrimagnetic spin resonator to an externally applied driving is experimentally studied. The observed multi–stability cannot be derived from any master equation that linearly depends on the spins' reduced density operator. Traditionally, the nonlinearity that is required in order to theoretically account for the observed multi–stability is introduced by implementing the method of Bosonization. Here, an alternative explanation, which is based on the hypothesis that disentanglement spontaneously occurs in quantum systems is explored. According to this hypothesis, time evolution is governed by a master equation having an added nonlinear term, which deterministically generates disentanglement. Experimental results are compared with predictions derived from both competing theoretical models. It is found that better agreement with data is obtained from the disentanglement–based model. This finding, together with a difficulty to justify the Bosonization–based model, indirectly support the spontaneous disentanglement hypothesis.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400587","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057903","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":"Effective and Robust Generation of Deterministic Magnon Schrödinger Cat States in the Hybrid System","authors":"Yu Wang,&nbsp;Yan Xia,&nbsp;Yi-Hao Kang","doi":"10.1002/qute.202400565","DOIUrl":"10.1002/qute.202400565","url":null,"abstract":"<p>A scheme is proposed for effective and robust generation of magnon Schrödinger cat states in the hybrid optomagnonical system. The Schrödinger cat states can be generated from the vacuum states and the physical model is easy to be implemented. It is worth noting that the effective normalized coupling strength of the optomagnonical system is able to reach strong coupling regime, which leads to a fast evolution process. Thus, the high fidelity and fast preparation of Schrödinger cat states can be achieved. Besides, the numerical simulations show that the scheme is robust against the decay caused by environment and the additive white Gaussian noise (AWGN). It is the hope that the scheme may open a new path to the fast generation of Schrödinger cat states in the hybrid system.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062451","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":"Nonreciprocal Strong Mechanical Squeezing Based on the Kerr Effect in Cavity-Magnon Optomechanical System","authors":"Jia-Le Tong,&nbsp;Yue Hao,&nbsp;Shao-Xiong Wu,&nbsp;Cheng-Hua Bai,&nbsp;Suying Bai","doi":"10.1002/qute.202400654","DOIUrl":"10.1002/qute.202400654","url":null,"abstract":"<p>In this study, a scheme is proposed to generate nonreciprocal strong mechanical squeezing in a cavity-magnon optomechanical system based on the Kerr nonlinearity of the yttrium-iron garnet (YIG) sphere. It is found that the magnon squeezing can be directly produced by the Kerr effect and it can induce strong mechanical squeezing through the squeezing transfer achieved by the cavity-magnon interaction and the optomechanical interaction. The results further show that the mechanical mode coupled to the cavity can achieve squeezing effect in the selected magnetic field direction, but not in the opposite one. Moreover, by properly adjusting the magnon effective detuning and the Kerr effect strength, the degree of squeezing of the mechanical mode can even beyond the 3-dB limit, and the optimal conditions for generating stronger squeezing are obtained. This work has important applications in the nonreciprocal quantum devices, quantum information processing, and quantum precision measurement.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057904","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":"Establishing and Investigating an Effective Atmosphere-Ocean Cross-Medium Propagation Model Based on GSM Beams","authors":"Jiao Wang,&nbsp;Xuyan Tie,&nbsp;Zhenkun Tan,&nbsp;Sichen Lei,&nbsp;Pengfei Wu,&nbsp;Xianghui Wang,&nbsp;Lijun Deng","doi":"10.1002/qute.202400591","DOIUrl":"10.1002/qute.202400591","url":null,"abstract":"<p>Using the Gaussian-Schell model (GSM) beam as the light source, this study creates a blue-green beam atmosphere-ocean cross-medium propagation model (AOCPM) based on the extended Huygens-Fresnel principle and the linear filtering method. The closed expression of the Cross Spectral Density Function (CSDF) of the GSM beam after propagation through atmospheric turbulence, atmosphere-ocean interface, and ocean turbulence are derived. And the correctness of the model is verified by simulating the changes in intensity, relative beam width, and speckle normalized intensity autocorrelation function during the propagation of the GSM beam through the atmosphere-ocean cross-medium under different parameters. The findings demonstrate that the intensity of the GSM beam after being propagated through the atmosphere-ocean medium presents a speckle-like Gaussian distribution, the intensity of the GSM beam gradually attenuates, the relative beam width gradually grows, and the speckle normalized intensity autocorrelation function gradually decreases as the turbulence intensity and propagation distance increase. In addition, the increase in wind speed at rough sea surface mainly leads to the attenuation of intensity. The work of this paper provides a new idea for the study of atmosphere-ocean cross-medium propagation of blue-green beams.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057905","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":"Distribution Relationship of Quantum Battery Capacity","authors":"Yiding Wang,&nbsp;Xiaofen Huang,&nbsp;Tinggui Zhang","doi":"10.1002/qute.202400652","DOIUrl":"10.1002/qute.202400652","url":null,"abstract":"<p>The distribution relationship of quantum battery capacity is investigated. First, it is proved that for two-qubit <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math>-states, the sum of the subsystem battery capacities does not exceed the total system's battery capacity, and the conditions are provided under which they are equal. Then define the difference between the total system's and subsystems' battery capacities as the residual battery capacity (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 <mi>B</mi>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <annotation>$RBC$</annotation>\u0000 </semantics></math>) and show that this can be divided into coherent and incoherent components. Furthermore, it is observed that this capacity monogamy relation for quantum batteries extends to general <span></span><math>\u0000 <semantics>\u0000 <mi>n</mi>\u0000 <annotation>$n$</annotation>\u0000 </semantics></math>-qubit <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math> states and any <span></span><math>\u0000 <semantics>\u0000 <mi>n</mi>\u0000 <annotation>$n$</annotation>\u0000 </semantics></math>-qubit <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math> state's battery capacity distribution can be optimized to achieve capacity gain through an appropriate global unitary evolution. Specifically, for general three-qubit <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math> states, stronger distributive relations are derived for battery capacity. Quantum batteries are believed to hold significant potential for outperforming classical counterparts in the future. These findings contribute to the development and enhancement of quantum battery theory.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 9","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062450","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":"Hardware-Efficient Quantum Random Access Memory Design with a Native Gate Set on Superconducting Platforms","authors":"Yun-Jie Wang,&nbsp;Sheng Zhang,&nbsp;Tai-Ping Sun,&nbsp;Ze-An Zhao,&nbsp;Xiao-Fan Xu,&nbsp;Xi-Ning Zhuang,&nbsp;Huan-Yu Liu,&nbsp;Cheng Xue,&nbsp;Peng Duan,&nbsp;Yu-Chun Wu,&nbsp;Zhao-Yun Chen,&nbsp;Guo-Ping Guo","doi":"10.1002/qute.202400519","DOIUrl":"10.1002/qute.202400519","url":null,"abstract":"<p>Quantum Random Access Memory (QRAM) is a critical component for enabling data queries in superposition, which is the cornerstone of quantum algorithms. Among various QRAM architectures, the bucket-brigade model stands out due to its noise resilience. This study presents a hardware-efficient native gate set <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>{</mo>\u0000 <mi>iSCZ</mi>\u0000 <mo>,</mo>\u0000 <mi>C</mi>\u0000 <mo>−</mo>\u0000 <mi>iSCZ</mi>\u0000 <mo>,</mo>\u0000 <msup>\u0000 <mi>S</mi>\u0000 <mo>†</mo>\u0000 </msup>\u0000 <mo>}</mo>\u0000 </mrow>\u0000 <annotation>$lbrace textsf {iSCZ}, textsf {C-iSCZ}, textsf {S}^{dagger }rbrace$</annotation>\u0000 </semantics></math> for implementing bucket-brigade QRAM on superconducting platforms. The experimental feasibility of the proposed gate set is demonstrated, showing high fidelity and reduced complexity. By leveraging the complementary control property in QRAM, the approach directly substitutes the conventional <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>{</mo>\u0000 <mi>SWAP</mi>\u0000 <mo>,</mo>\u0000 <mi>CSWAP</mi>\u0000 <mo>}</mo>\u0000 </mrow>\u0000 <annotation>$lbrace textsf {SWAP}, textsf {CSWAP} rbrace$</annotation>\u0000 </semantics></math> gates with the new gate set, eliminating decomposition overhead and significantly reducing circuit depth and gate count.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944939","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":"Heteroepitaxial (111) Diamond Quantum Sensors with Preferentially Aligned Nitrogen-Vacancy Centers for an Electric Vehicle Battery Monitor","authors":"Kenichi Kajiyama,&nbsp;Moriyoshi Haruyama,&nbsp;Yuji Hatano,&nbsp;Hiromitsu Kato,&nbsp;Masahiko Ogura,&nbsp;Toshiharu Makino,&nbsp;Hitoshi Noguchi,&nbsp;Takeharu Sekiguchi,&nbsp;Takayuki Iwasaki,&nbsp;Mutsuko Hatano","doi":"10.1002/qute.202400400","DOIUrl":"10.1002/qute.202400400","url":null,"abstract":"<p>A platform for heteroepitaxial (111) chemical vapor deposition (CVD) diamond quantum sensors with preferentially aligned nitrogen vacancy (NV) centers on a large substrate is developed, and its operation as an electric vehicle (EV) battery monitor is demonstrated. A self-standing heteroepitaxial CVD diamond film with a (111) orientation and a thickness of 150 µm is grown on a non-diamond substrate and subsequently separated from it. The high uniformity and crystallinity of the (111)-oriented diamond is confirmed. A 150-µm thick NV-diamond layer is then deposited on the heteroepitaxial diamond. The <i>T</i>₂ value measured by confocal microscopy is 20 µs, which corresponds to substitutional nitrogen defect concentration of 8 ppm. The nitrogen-vacancy concentration and <i>T</i>₂^* are estimated to be 0.05 ppm and 0.05 µs by continuous wave optically detected magnetic resonance (CW-ODMR) spectroscopy in a fiber-top sensor configuration. In a gradiometer, where two sensors are placed on both sides of the busbar, the noise floor is 17 nT/Hz^0.5 in the frequency range of 10–40 Hz without magnetic shielding. The Allan deviation of the magnetic field noise in the laboratory is below 0.3 µT, which corresponds to a busbar current of 10 mA, in the accumulation time range of 10 ms to 100 s.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 4","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400400","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793328","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":"Quantifying Quantum Steering with Limited Resources: A Semi-supervised Machine Learning Approach","authors":"Yansa Lu,&nbsp;Zhihua Chen,&nbsp;Zhihao Ma,&nbsp;Shao-Ming Fei","doi":"10.1002/qute.202400521","DOIUrl":"10.1002/qute.202400521","url":null,"abstract":"<p>Quantum steering, an intermediate quantum correlation lying between entanglement and nonlocality, has emerged as a critical quantum resource for a variety of quantum information processing tasks such as quantum key distribution and true randomness generation. The ability to detect and quantify quantum steering is crucial for these applications. Semi-definite programming (SDP) has proven to be a valuable tool to quantify quantum steering. However, the challenge lies in the fact that the optimal measurement strategy is not priori known, making it time-consuming to compute the steerable measure for any given quantum state. Furthermore, the utilization of SDP requires full information of the quantum state, necessitating quantum state tomography, which can be complex and resource-consuming. In this work, the semi-supervised self-training model is used to estimate the steerable weight, a pivotal measure of quantum steering. The model can be trained using a limited amount of labeled data, thus reducing the time for labeling. The features are constructed by the probabilities derived by performing three sets of projective measurements under arbitrary local unitary transformations on the target states, circumventing the need for quantum tomography. The model demonstrates robust generalization capabilities and can achieve high levels of precision with limited resources.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"8 8","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832939","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}