Advanced quantum technologies最新文献

{"title":"Birefringent Spin-Photon Interface Generates Polarization Entanglement","authors":"Nikita Leppenen,&nbsp;Dmitry S. Smirnov","doi":"10.1002/qute.202400193","DOIUrl":"10.1002/qute.202400193","url":null,"abstract":"<p>A spin-photon interface based on the luminescence of a singly charged quantum dot in a micropillar cavity allows for the creation of photonic entangled states. Current devices suffer from cavity birefringence, which limits the generation of spin-photon entanglement. In this study, we conduct a theoretical analysis of the light absorption and emission by the interface with an anisotropic cavity and derive the maximal excitation and spin-photon entanglement conditions. It is shown that the concurrence of the spin-photon state equal to one and complete quantum dot population inversion can be reached for a micropillar cavity with any degree of birefringence by tuning the quantum dot resonance strictly between the cavity modes. This sweet spot is also valid for generating a multiphoton cluster state, as demonstrated by calculating the three-tangle and fidelity with the maximally entangled state.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218915","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":"Error-Heralded and Deterministic Interconversion Between W State and Greenberger–Horne–Zeilinger State with Faithful Quantum Gates in Decoherence-Free-Subspace","authors":"Fang-Fang Du,&nbsp;Ming Ma,&nbsp;Qiu-lin Tan","doi":"10.1002/qute.202400322","DOIUrl":"10.1002/qute.202400322","url":null,"abstract":"<p>The interconversion of a variety of entangled states can facilitate the information transmission and decline the risk of error rates. Here two faithful protocols to achieve deterministic interconversion between three-logic-qubit W state and three-logic-qubit Greenberger–Horne–Zeilinger state in decoherence-free subspace (DFS), resorting to the state-selective property of the quantum dot (QD)-cavity systems and robust-fidelity quantum control gates are presented. Moreover, the single-photon detectors introduced can effectively herald and mitigate potential failures from imperfect interaction between the QD-cavity system and photons, significantly enhancing experimental feasibility. Through comprehensive analysis and evaluation, the protocols demonstrate exceptional conversion efficiencies and deliver near-perfect fidelities. Additionally, the DFS makes system coherence over extended periods to overcome the decoherence effect caused by specific environmental noise, paving the way for quantum information processing.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218919","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":"Analysis for Satellite-Based High-Dimensional Extended B92 and High-Dimensional BB84 Quantum Key Distribution","authors":"Arindam Dutta,&nbsp; Muskan,&nbsp;Subhashish Banerjee,&nbsp;Anirban Pathak","doi":"10.1002/qute.202400149","DOIUrl":"https://doi.org/10.1002/qute.202400149","url":null,"abstract":"<p>A systematic analysis of the advantages and challenges associated with the satellite-based implementation of the high dimensional extended B92 (HD-Ext-B92) and high-dimensional BB84 (HD-BB84) protocol is analyzed. The method used earlier for obtaining the key rate for the HD-Ext-B92 is modified here and subsequently the variations of the key rate, probability distribution of key rate (PDR), and quantum bit error rate (QBER) with respect to dimension and noise parameter of a depolarizing channel is studied using the modified key rate equation. Further, the variations of average key rate (per pulse) with zenith angle and link length in different weather conditions in day and night considering extremely low noise for dimension <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 <mo>=</mo>\u0000 <mn>32</mn>\u0000 </mrow>\u0000 <annotation>${rm d}=32$</annotation>\u0000 </semantics></math> are investigated using elliptic beam approximation. The effectiveness of the HD-(extended) protocols used here in creating satellite-based quantum key distribution links (both up-link and down-link) are established by appropriately modeling the atmosphere and analyzing the variation of average key rates with the probability distribution of the transmittance (PDT). The analysis performed here has revealed that in higher dimensions, HD-BB84 outperforms HD-Ext-B92 in terms of both key rate and noise tolerance. However, HD-BB84 experiences a more pronounced saturation of QBER in high dimensions.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 11","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642355","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":"Stationary Quantum Entanglement and Asymmetric Steering in Cavity Magnonic System with Floquet Field and Coherent Feedback","authors":"Si-Yu Guan,&nbsp;Hong-Fu Wang,&nbsp;Xuexi Yi","doi":"10.1002/qute.202400281","DOIUrl":"10.1002/qute.202400281","url":null,"abstract":"<p>A scheme is proposed to prepare quantum entanglement and quantum steering between two indirectly coupled microwave cavity modes within a hybrid cavity magnonic system. The system consists of two microwave cavities individually coupled to a common YIG sphere driven by a two-tone Floquet field, while the output field of the second microwave cavity is fed back into the input port of the first microwave cavity via a coherent feedback loop. Floquet driving can effectively generate two interactions between magnons and photons. Magnons with higher dissipation can serve as a cooling channel for the two cavity modes. Optimal quantum correlations between the cavity modes can be achieved when the competition between these two interactions reaches equilibrium. Subsequently, a comparative analysis is performed on the evolution of quantum correlation with and without coherent feedback, revealing that the presence of a coherent feedback loop in the system not only significantly enhances entanglement and steering but also induces inherent asymmetry in quantum steering regardless of the decay rates within subsystems. Moreover, under the influence of the coherent feedback loop, the enhanced quantum correlations exhibit increased robustness against rising environmental temperatures. This work significantly expands the validity of implementation and provides a promising avenue for the preparation of stable quantum correlations.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218918","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":"A Computation-Strengthened High-Dimensional Three-Qudit Toffoli Gate","authors":"Fang-Fang Du,&nbsp;Xue-Mei Ren,&nbsp;Qiu-Lin Tan","doi":"10.1002/qute.202400313","DOIUrl":"10.1002/qute.202400313","url":null,"abstract":"<p>A high-dimensional quantum gate not only enables the processing of more information through parallel quantum channels but also enhances fault tolerance in a higher Hilbert space. In this paper, a protocol is presented for implementing a three-qudit <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>4</mn>\u0000 <mo>×</mo>\u0000 <mn>4</mn>\u0000 <mo>×</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 <annotation>$4times 4times 4$</annotation>\u0000 </semantics></math>-Dimensional (D) Toffoli gate for a hybrid system, where the first control qudit, the second control qudit, and the target qudit of four dimension are encoded in the spatial-polarization state of a flying photon, the electron-spin state of the first two quantum dots (QDs), and the one of the remaining two QDs, respectively. Besides, the high-dimensional Toffoli gate does not require any assistance. Moreover, the gate operates deterministically in principle, as the photon is easy to manipulate feasibly using simple optical elements, and four QDs have a long electron-spin coherent time used for storage and manipulation. Furthermore, the success probability and fidelity of the high-dimensional Toffoli gate, in alignment with current technological capabilities, demonstrate satisfactory results. This indicates that it is feasible in experimental settings and promises a quantum computing paradigm that excels in speed, error resilience, and scalability for intricate quantum operations.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218920","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":"Single-Beam Vector Atomic Magnetometer with High Dynamic Range Based on Magnetic Field Modulation","authors":"Junlin Chen,&nbsp;Liwei Jiang,&nbsp;Xin Zhao,&nbsp;Jiali Liu,&nbsp;Yanchao Chai,&nbsp;Mengnan Tian,&nbsp;Zhenglong Lu","doi":"10.1002/qute.202400289","DOIUrl":"10.1002/qute.202400289","url":null,"abstract":"&lt;p&gt;In geophysical exploration and similar applications, magnetometers need to capture the complete magnetic field information, including both the magnitude and direction. Despite recent advancements in vector atomic magnetometers, they often face issues that hinder practical use. To overcome this, a high dynamic range single-beam vector atomic magnetometer based on the nonlinear magneto-optical rotation (NMOR) effect is proposed, utilizing a closed-loop system with applied three-axis modulation magnetic fields. In this method, closed-loop measurement is achieved using a phase-locked loop (PLL), with the frequencies of the applied modulation magnetic fields being significantly higher than the response bandwidth of the PLL. This allows directional information to be extracted from the modulation fields response signal and magnitude information from the PLL-locked frequency. A theoretical analysis of the proposed method is conducted by establishing an NMOR atomic magnetometer model under arbitrary magnetic field directions and deriving the method for obtaining the magnetic field direction. In further experimental validation, it is demonstrated that the vector atomic magnetometer can achieve measurement of three-axis vector magnetic fields, with a sensitivity of approximately &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;500&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;fT&lt;/mi&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msqrt&gt;\u0000 &lt;mi&gt;Hz&lt;/mi&gt;\u0000 &lt;/msqrt&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$500nobreakspace mathrm{fT (sqrt {Hz})^{-1}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for magnetic field magnitude, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.29&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;mrad&lt;/mi&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msqrt&gt;\u0000 &lt;mi&gt;Hz&lt;/mi&gt;\u0000 &lt;/msqrt&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$0.29nobreakspace mathrm{mrad (sqrt {Hz})^{-1}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for inclination angle, and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.94&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;mrad&lt;/mi&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218921","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":"Laser Beam Induced Charge Collection for Defect Mapping and Spin State Readout in Diamond","authors":"Dominic Reinhardt,&nbsp;Julia Heupel,&nbsp;Cyril Popov,&nbsp;Ralf Wunderlich","doi":"10.1002/qute.202400237","DOIUrl":"10.1002/qute.202400237","url":null,"abstract":"<p>The detection of laser-induced photo-currents in diamond is shown with about 100 fA resolution in the pico- to nanoampere range. A micro-electronic approach enables to work without using lock-in techniques. For that purpose, a commercially available and low-cost precision integrating amplifier is utilized on a home-built printed circuit board. This technique is applied to three different diamond samples with different defect concentrations. Two ultra-pure diamond samples with shallow implanted defects, predominantly nitrogen-vacancy (NV) centers and substitutional nitrogen (P1 centers), are investigated. The third sample is an electron-irradiated type Ib diamond with a much higher intrinsic defect concentration. For all samples, spatially resolved photo-current maps as well as laser power and bias voltage-dependent measurements are recorded. Furthermore, photo-currents are successfully recorded without an applied bias voltage. Finally, the technique is used to perform continuous wave photoelectric detection of magnetic resonances (PDMR) using NV centers. The presented approach paves the way for time-resolved photo-current measurements of individual defects and pulsed PDMR measurements without lock-in technology.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227430","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":"Spontaneous Disentanglement of Indistinguishable Particles","authors":"Eyal Buks","doi":"10.1002/qute.202400248","DOIUrl":"10.1002/qute.202400248","url":null,"abstract":"<p>A master equation containing a nonlinear term that gives rise to disentanglement has been recently explored. Here, a modified version, which is applicable for indistinguishable particles, is proposed, and studied for both the Bose–Hubbard and the Fermi–Hubbard models. It is found for both Bosons and Fermions that disentanglement can give rise to quantum phase transitions.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218917","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":"Front Cover: Generating Microwave Signals with Enhancive Amplitudes Using Superconductor Single Flux Quantum Pulses for Controlling Quantum Bit (Adv. Quantum Technol. 8/2024)","authors":"Hongxiang Shen,&nbsp;Yuxing He,&nbsp;Zeyu Han,&nbsp;Zongyuan Li,&nbsp;Wenhui Luo,&nbsp;Lan Cheng,&nbsp;Yanyi Luo,&nbsp;Bo Jing,&nbsp;Nobuyuki Yoshikawa","doi":"10.1002/qute.202470020","DOIUrl":"https://doi.org/10.1002/qute.202470020","url":null,"abstract":"<p>This cover image illustrates the generation of microwave waveforms for qubit control by transforming superconducting single-flux-quantum (SFQ) pulses through a filtering network. The output microwave can be modulated by managing the condition of an SFQ pulse pair. Specifically, the reverse-polarity pulse-pair (RPPP) method enables maximum output amplitude and precise control over the initial phase of the microwave. This approach facilitates on-chip qubit control in a cryogenic environment, significantly reducing thermal noise and interconnecting cables, which is crucial for large-scale quantum computing. For further details see article number 2400001 by Hongxiang Shen, Yuxing He, Nobuyuki Yoshikawa, 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 8","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202470020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141986109","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":"Positional Accuracy of 3D Printed Quantum Emitter Fiber Couplers","authors":"Ksenia Weber,&nbsp;Simon Thiele,&nbsp;Mario Hentschel,&nbsp;Alois Herkommer,&nbsp;Harald Giessen","doi":"10.1002/qute.202400135","DOIUrl":"10.1002/qute.202400135","url":null,"abstract":"<p>Precise positioning of optical elements plays a key role in the performance of optical systems. While additive manufacturing techniques such as 3D printing enable the creation of entire complex micro-objectives in one step, thus rendering lens alignment unnecessary, certain applications require precise positional alignment of the printing process with respect to the substrate. For example, in order to efficiently couple quantum emitters to single-mode fibers, which is a crucial step in the development of real world quantum networks, precise alignment between the emitter, the coupling optics, and the single-mode fiber is of utmost importance. In this work, the positioning accuracy of a Photonics Professional GT (Nanoscribe GmbH) 3D printing machine is evaluated by using the integrated piezo stage to align to gold markers that is manufactured via e-beam lithography. By running a statistical analysis of 38 printing cycles, a mean positional error of only 80 nm is determined. Additionally, an entire system is 3D printed that can couple quantum emitters to optical single-mode fibers. Examining the focal spot of the 3D printed micro-optics, a positional accuracy of ≈ 1 µm in all three dimensions is found, as well as excellent quality of the focal spot.</p>","PeriodicalId":72073,"journal":{"name":"Advanced quantum technologies","volume":"7 11","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/qute.202400135","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218948","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}