Quadrature-Symmetric PulsePol for Robust Quantum Control Beyond the Ideal Pulse Approximation
Center for Quantum and Topological Systems, New York University Abu Dhabi（纽约大学阿布扎比分校量子与拓扑系统中心）；Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University（奥胡斯大学跨学科纳米科学中心（iNANO）和化学系）；Indian Institute of Science Education and Research, Bhopal（印度科学教育研究所博帕尔分校）；Tata Institute of Fundamental Research Hyderabad（泰姬玛哈底拉基础研究所海得拉巴分所）；Department of Chemistry, New York University Abu Dhabi（纽约大学阿布扎比分校化学系）
Mayur Jhamnani, Venkata SubbaRao Redrouthu, Jose P. Carvalho, Ethan Feldman, Anders B. Nielsen, Phani Kumar, Niels Chr. Nielsen, P. K. Madhu, Asif Equbal
PulsePol is an elegantly designed pulse-sequence-based quantum control scheme that enables polarization transfer between electron and nuclear spins, for example, in nitrogen-vacancy (NV) centers. However, previous analyses of PulsePol assumed very strong, near-ideal, instantaneous microwave pulses, which is rarely achievable at higher magnetic fields. We revisit the PulsePol scheme under finite-pulse constraints and show that its performance significantly degrades due to finite-pulse effects. Using bimodal Floquet theory, we identify the symmetry-breaking mechanism responsible for this deterioration in fidelity. By phase adjustment, we reestablish the proper symmetry of the interaction-frame spin Hamiltonian, leading to a sequence called Q-PulsePol, where "Q" reflects the restored quadrature symmetry. Our results demonstrate robustness to finite-pulse effects and improved polarization transfer efficiency, establishing Q-PulsePol as a practical and reliable scheme for bulk hyperpolarization of nuclear spins in solids using a single-mode (zero-quantum or double-quantum) transfer. This work bridges idealized quantum control with realistic pulse engineering, establishing design rules for spin-based quantum control protocols.
Quantified convergence of general homodyne measurements with applications to continuous variable quantum computing
National Institute of Standards and Technology（美国国家标准与技术研究院）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；Center for Theory of Quantum Matter, University of Colorado, Boulder（科罗拉多大学博尔德分校量子物质理论中心）；Department of Physics, University of Colorado, Boulder（科罗拉多大学博尔德分校物理系）；IonQ
Pulse-resolved post-generation phase control of squeezed light at 93 MHz with a bulk lithium-niobate modulator
Università degli Studi di Milano（米兰大学）；Istituto Nazionale di Fisica Nucleare, Sezione di Milano（意大利国家核物理研究所米兰分部）；Istituto di Fotonica e Nanotecnologie - CNR（光子与纳米技术研究所-意大利国家研究委员会）
Quantum correlations and fluctuations in the pulsed light produced by a synchronously pumped optical parametric oscillator below its oscillation threshold
Pulse characterization at the single-photon level through chronocyclic $Q$-function measurements
Paderborn University, Integrated Quantum Optics, Institute for Photonic Quantum Systems (PhoQS)（帕德博恩大学，集成量子光学，光子量子系统研究所 (PhoQS)）；Department of Optics, Palacký University（奥尔米茨帕拉茨基大学光学系）
Simultaneous gates in frequency-crowded multilevel systems using fast, robust, analytic control shapes
我们提出了一个少参数的脉冲实现一个广泛的同时单量子比特旋转频率拥挤的多级系统的anastrance。具体来说，我们考虑一个系统的两个qutrits的工作和泄漏过渡遭受频谱拥挤（失谐由$δ$）。为了实现精确的可控性，我们利用两个驱动领域（每个有两个quadratures）在两个不同的色调，以实现任意的同时旋转。扩展波形的汉宁窗口，我们展示了如何分析脉冲包含平滑和复合脉冲功能可以很容易地实现门误差小于$10^{-4}$，大大优于已知的绝热技术。此外，我们发现Schutjens等人[Phys. Rev. A 88，052330（2013）]的WahWah方法的推广，该方法允许超过量子速度限制的所有门时间的精确分离的单量子比特旋转。我们发现在所有情况下，量子速度限制略低于$2π/δ$的门时间，并表明我们的脉冲是强大的对系统参数和过滤的变化，由于传递函数，使它们适合实验实现。
Quantum-Key Distribution using Decoy Pulses to Combat Photon-Number Splitting by Eavesdropper: An Event-by-Event Impairment Enumeration Approach for Performance Evaluation and Design
