Quantum Science and Technology最新文献_第10页

Trapping Ba+ with seven-fold enhanced efficiency utilizing an autoionizing resonance 利用自电离共振将捕获 Ba+ 的效率提高七倍

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-05-02 DOI: 10.1088/2058-9565/ad3f41

Noah Greenberg, Brendan M White, Pei Jiang Low and Crystal Senko

引用次数: 0

Operational Markovianization in randomized benchmarking 随机基准测试中的操作马尔可夫化

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-29 DOI: 10.1088/2058-9565/ad3f44

P Figueroa-Romero, M Papič, A Auer, M-H Hsieh, K Modi and I de Vega

{"title":"Operational Markovianization in randomized benchmarking","authors":"P Figueroa-Romero, M Papič, A Auer, M-H Hsieh, K Modi and I de Vega","doi":"10.1088/2058-9565/ad3f44","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3f44","url":null,"abstract":"A crucial task to obtain optimal and reliable quantum devices is to quantify their overall performance. The average fidelity of quantum gates is a particular figure of merit that can be estimated efficiently by randomized benchmarking (RB). However, the concept of gate-fidelity itself relies on the crucial assumption that noise behaves in a predictable, time-local, or so-called Markovian manner, whose breakdown can naturally become the leading source of errors as quantum devices scale in size and depth. We analytically show that error suppression techniques such as dynamical decoupling (DD) and Pauli-twirling can operationally Markovianize RB: (i) fast DD reduces non-Markovian RB to an exponential decay plus longer-time corrections, while on the other hand, (ii) Pauli-twirling generally does not affect the average, but (iii) it always suppresses the variance of such RB outputs. We demonstrate these effects numerically with a qubit noise model. Our results show that simple and efficient error suppression methods can simultaneously tame non-Markovian noise and allow for standard and reliable gate quality estimation, a fundamentally important task in the path toward fully functional quantum devices.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140814426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topologically protected subradiant cavity polaritons through linewidth narrowing enabled by dissipationless edge states 通过无耗散边缘态的线宽收窄实现拓扑保护亚辐射空腔极化子

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-25 DOI: 10.1088/2058-9565/ad3f46

Yu-Wei Lu, Jing-Feng Liu, Haoxiang Jiang and Zeyang Liao

{"title":"Topologically protected subradiant cavity polaritons through linewidth narrowing enabled by dissipationless edge states","authors":"Yu-Wei Lu, Jing-Feng Liu, Haoxiang Jiang and Zeyang Liao","doi":"10.1088/2058-9565/ad3f46","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3f46","url":null,"abstract":"Cavity polaritons derived from strong light–matter interaction provide a basis for efficient manipulation of quantum states via cavity field. Polaritons with narrow linewidth and long lifetime are appealing in applications, such as quantum sensing and storage. Here, we propose a prototypical arrangement to implement a whispering-gallery-mode resonator with one-dimensional topological atom mirror, which allows to boost the lifetime of cavity polaritons over an order of magnitude. This considerable enhancement attributes to the coupling of polaritonic states to dissipationless edge states protected by the topological bandgap of atom mirror that suppresses the leakage of cavity modes. When exceeding the width of Rabi splitting, topological bandgap can further reduce the dissipation from polaritonic states to bulk states, giving arise to subradiant cavity polaritons with extremely sharp linewidth. The resultant Rabi oscillation experiences decay rate lower than the free-space decay of a single quantum emitter. Inheriting from the topologically protected properties of edge states, the subradiance of cavity polaritons can be preserved in disordered atom mirror with moderate perturbations involving the atomic frequency, interaction strengths and location fluctuations. Our work opens up a new paradigm of topology-engineered quantum states with robust quantum coherence for future applications in quantum computing and network.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An optically pumped magnetic gradiometer for the detection of human biomagnetism 用于检测人体生物磁性的光泵浦磁性梯度仪

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-25 DOI: 10.1088/2058-9565/ad3d81

Harry Cook, Yulia Bezsudnova, Lari M Koponen, Ole Jensen, Giovanni Barontini and Anna U Kowalczyk

引用次数: 0

Bilayer ion trap design for 2D arrays 二维阵列的双层离子阱设计

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-25 DOI: 10.1088/2058-9565/ad3f43

Gavin N Nop, Jonathan D H Smith, Daniel Stick and Durga Paudyal

{"title":"Bilayer ion trap design for 2D arrays","authors":"Gavin N Nop, Jonathan D H Smith, Daniel Stick and Durga Paudyal","doi":"10.1088/2058-9565/ad3f43","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3f43","url":null,"abstract":"Junctions are fundamental elements that support qubit locomotion in two-dimensional ion trap arrays and enhance connectivity in emerging trapped-ion quantum computers. In surface ion traps they have typically been implemented by shaping radio frequency (RF) electrodes in a single plane to minimize the disturbance to the pseudopotential. However, this method introduces issues related to RF lead routing that can increase power dissipation and the likelihood of voltage breakdown. Here, we propose and simulate a novel two-layer junction design incorporating two perpendicularly rotoreflected (rotated, then reflected) linear ion traps. The traps are vertically separated, and create a trapping potential between their respective planes. The orthogonal orientation of the RF electrodes of each trap relative to the other provides perpendicular axes of confinement that can be used to realize transport in two dimensions. While this design introduces manufacturing and operating challenges, as now two separate structures have to be precisely positioned relative to each other in the vertical direction and optical access from the top is obscured, it obviates the need to route RF leads below the top surface of the trap and eliminates the pseudopotential bumps that occur in typical junctions. In this paper the stability of idealized ion transfer in the new configuration is demonstrated, both by solving the Mathieu equation analytically to identify the stable regions and by numerically modeling ion dynamics. Our novel junction layout has the potential to enhance the flexibility of microfabricated ion trap control to enable large-scale trapped-ion quantum computing.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140648975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling non-Markovian noise in driven superconducting qubits 驱动超导量子比特中的非马尔可夫噪声建模

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-25 DOI: 10.1088/2058-9565/ad3d7e

Abhishek Agarwal, Lachlan P Lindoy, Deep Lall, François Jamet and Ivan Rungger

{"title":"Modelling non-Markovian noise in driven superconducting qubits","authors":"Abhishek Agarwal, Lachlan P Lindoy, Deep Lall, François Jamet and Ivan Rungger","doi":"10.1088/2058-9565/ad3d7e","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3d7e","url":null,"abstract":"Non-Markovian noise can be a significant source of errors in superconducting qubits. We develop gate sequences utilising mirrored pseudoidentities that allow us to characterise and model the effects of non-Markovian noise on both idle and driven qubits. We compare three approaches to modelling the observed noise: (i) a Markovian noise model, (ii) a model including interactions with a two-level system (TLS), (iii) a model utilising the post Markovian master equation, which we show to be equivalent to the qubit-TLS model in certain regimes. When running our noise characterisation circuits on a superconducting qubit device we find that purely Markovian noise models cannot reproduce the experimental data. Our model based on a qubit-TLS interaction, on the other hand, is able to closely capture the observed experimental behaviour for both idle and driven qubits. We investigate the stability of the noise properties of the hardware over time, and find that the parameter governing the qubit-TLS interaction strength fluctuates significantly even over short time-scales of a few minutes. Finally, we evaluate the changes in the noise parameters when increasing the qubit drive pulse amplitude. We find that although the hardware noise parameters fluctuate significantly over different days, their drive pulse induced relative variation is rather well defined within computed uncertainties: both the phase error and the qubit-TLS interaction strength change significantly with the pulse strength, with the phase error changing quadratically with the amplitude of the applied pulse. Since our noise model can closely describe the behaviour of idle and driven qubits, it is ideally suited to be used in the development of quantum error mitigation and correction methods.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Parameter estimation from quantum-jump data using neural networks 利用神经网络从量子跃迁数据中进行参数估计

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-25 DOI: 10.1088/2058-9565/ad3c68

Enrico Rinaldi, Manuel González Lastre, Sergio García Herreros, Shahnawaz Ahmed, Maryam Khanahmadi, Franco Nori and Carlos Sánchez Muñoz

{"title":"Parameter estimation from quantum-jump data using neural networks","authors":"Enrico Rinaldi, Manuel González Lastre, Sergio García Herreros, Shahnawaz Ahmed, Maryam Khanahmadi, Franco Nori and Carlos Sánchez Muñoz","doi":"10.1088/2058-9565/ad3c68","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3c68","url":null,"abstract":"We present an inference method utilizing artificial neural networks for parameter estimation of a quantum probe monitored through a single continuous measurement. Unlike existing approaches focusing on the diffusive signals generated by continuous weak measurements, our method harnesses quantum correlations in discrete photon-counting data characterized by quantum jumps. We benchmark the precision of this method against Bayesian inference, which is optimal in the sense of information retrieval. By using numerical experiments on a two-level quantum system, we demonstrate that our approach can achieve a similar optimal performance as Bayesian inference, while drastically reducing computational costs. Additionally, the method exhibits robustness against the presence of imperfections in both measurement and training data. This approach offers a promising and computationally efficient tool for quantum parameter estimation with photon-counting data, relevant for applications such as quantum sensing or quantum imaging, as well as robust calibration tasks in laboratory-based settings.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Remote cross-resonance gate between superconducting fixed-frequency qubits 超导定频量子位之间的远程交叉共振门

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-24 DOI: 10.1088/2058-9565/ad3f47

Mari Ohfuchi and Shintaro Sato

{"title":"Remote cross-resonance gate between superconducting fixed-frequency qubits","authors":"Mari Ohfuchi and Shintaro Sato","doi":"10.1088/2058-9565/ad3f47","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3f47","url":null,"abstract":"High-fidelity quantum state transfer and remote entanglement between superconducting fixed-frequency qubits have not yet been realized. In this study, we propose an alternative remote cross-resonance gate. Considering multiple modes of a superconducting coaxial cable connecting qubits, we must find conditions under which the cross-resonance gate operates with a certain accuracy even in the presence of qubit frequency shifts due to manufacturing errors. For 0.25- and 0.5 m cables, remote cross-resonance gates with a concurrence of in entanglement generation are obtained even with ±10 MHz frequency shifts. For a 1 m cable with a narrow mode spacing, a concurrence of 99.5% is achieved by reducing the coupling between the qubits and cable. The optimized echoed raised-cosine pulse duration is 150–400 ns, which is similar to the operation time of cross-resonance gates between neighboring qubits on a chip. The dissipation through the cable modes does not considerably affect the obtained results. Such high-precision quantum interconnects pave the way not only for scaling up quantum computer systems but also for nonlocal connections on a chip.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140642738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Efficient quantum algorithm for all quantum wavelet transforms 所有量子小波变换的高效量子算法

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-22 DOI: 10.1088/2058-9565/ad3d7f

Mohsen Bagherimehrab, Alán Aspuru-Guzik

{"title":"Efficient quantum algorithm for all quantum wavelet transforms","authors":"Mohsen Bagherimehrab, Alán Aspuru-Guzik","doi":"10.1088/2058-9565/ad3d7f","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3d7f","url":null,"abstract":"Wavelet transforms are widely used in various fields of science and engineering as a mathematical tool with features that reveal information ignored by the Fourier transform. Unlike the Fourier transform, which is unique, a wavelet transform is specified by a sequence of numbers associated with the type of wavelet used and an order parameter specifying the length of the sequence. While the quantum Fourier transform, a quantum analog of the classical Fourier transform, has been pivotal in quantum computing, prior works on quantum wavelet transforms (QWTs) were limited to the second and fourth order of a particular wavelet, the Daubechies wavelet. Here we develop a simple yet efficient quantum algorithm for executing any wavelet transform on a quantum computer. Our approach is to decompose the kernel matrix of a wavelet transform as a linear combination of unitaries (LCU) that are compilable by easy-to-implement modular quantum arithmetic operations and use the LCU technique to construct a probabilistic procedure to implement a QWT with a <italic toggle=\"yes\">known</italic> success probability. We then use properties of wavelets to make this approach deterministic by a few executions of the amplitude amplification strategy. We extend our approach to a multilevel wavelet transform and a generalized version, the packet wavelet transform, establishing computational complexities in terms of three parameters: the wavelet order <italic toggle=\"yes\">M</italic>, the dimension <italic toggle=\"yes\">N</italic> of the transformation matrix, and the transformation level <italic toggle=\"yes\">d</italic>. We show the cost is logarithmic in <italic toggle=\"yes\">N</italic>, linear in <italic toggle=\"yes\">d</italic> and superlinear in <italic toggle=\"yes\">M</italic>. Moreover, we show the cost is independent of <italic toggle=\"yes\">M</italic> for practical applications. Our proposed QWTs could be used in quantum computing algorithms in a similar manner to their well-established counterpart, the quantum Fourier transform.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140640454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Neural-network-designed three-qubit gates robust against charge noise and crosstalk in silicon 神经网络设计的三量子比特硅门可抵御电荷噪声和串扰

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-04-22 DOI: 10.1088/2058-9565/ad3d06

David W Kanaar, J P Kestner

{"title":"Neural-network-designed three-qubit gates robust against charge noise and crosstalk in silicon","authors":"David W Kanaar, J P Kestner","doi":"10.1088/2058-9565/ad3d06","DOIUrl":"https://doi.org/10.1088/2058-9565/ad3d06","url":null,"abstract":"Spin qubits in semiconductor quantum dots are a promising platform for quantum computing, however, scaling to large systems is hampered by crosstalk and charge noise. Crosstalk here refers to the unwanted off-resonant rotation of idle qubits during the resonant rotation of the target qubit. For a three-qubit system with crosstalk and charge noise, it is difficult to analytically create gate protocols that produce three-qubit gates, such as the Toffoli gate, directly in a single shot instead of through the composition of two-qubit gates. Therefore, we numerically optimize a physics-informed neural network to produce theoretically robust shaped pulses that generate a Toffoli-equivalent gate. Additionally, robust <inline-formula>\u0000<tex-math><?CDATA $frac{pi}{2}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mfrac><mml:mi>π</mml:mi><mml:mn>2</mml:mn></mml:mfrac></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"qstad3d06ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>\u0000<italic toggle=\"yes\">X</italic> and Controlled-Z gates are also presented in this work to create a universal set of gates robust against charge noise. The robust pulses maintain an infidelity of 10<sup>−3</sup> for average quasistatic fluctuations in the voltage of up to a few mV instead of tenths of mV for non-robust pulses.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140640458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0