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Related papers: Optimal control for one-qubit quantum sensing

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Quantum key distribution (QKD) has emerged as a promising solution to protect current cryptographic systems against the threat of quantum computers. As QKD transitions from laboratories to real-world applications, its implementation under…

Quantum Physics · Physics 2026-05-22 Hashir Kuniyil , Saif Al-Kuwari , Asad Ali , Artur Czerwinski , Syed M. Arslan

Simultaneously estimating multiple parameters at the ultimate limit is a central challenge in quantum metrology, often hindered by inherent incompatibilities in optimal estimation strategies. At its most extreme, this incompatibility…

We introduce a new approach to assess the error of control problems we aim to optimize. The method offers a strategy to define new control pulses that are not necessarily optimal but still able to yield an error not larger than some fixed a…

Quantum Physics · Physics 2011-07-22 Antonio Negretti , Rosario Fazio , Tommaso Calarco

We propose and analyze a new approach based on quantum error correction (QEC) to improve quantum metrology in the presence of noise. We identify the conditions under which QEC allows one to improve the signal-to-noise ratio in…

Quantum Physics · Physics 2014-04-29 Eric M. Kessler , Igor Lovchinsky , Alexander O. Sushkov , Mikhail D. Lukin

Nitrogen-vacancy centers in diamond allow measurement of environment properties such as temperature, magnetic and electric fields at nanoscale level, of utmost relevance for several research fields, ranging from nanotechnologies to…

The nitrogen-vacancy (NV) center spin represents an appealing candidate for quantum information processing. Besides the widely used microwave control, its coherent manipulation may also be achieved using laser as mediated by the excited…

Quantum Physics · Physics 2022-05-05 Jiazhao Tian , Tianyi Du , Yu Liu , Haibin Liu , Fangzhou Jin , Ressa S. Said , Jianming Cai

Accurate frequency estimation of oscillating signals over a broad bandwidth is a central task in quantum sensing, yet it is often compromised by spurious responses to higher-order harmonics in realistic multi-frequency environments. Here we…

Quantum Physics · Physics 2026-01-28 Si-Qi Chen , Qi-Tao Duan , Teng Li , He Lu

Quantum optimal control is a technique for controlling the evolution of a quantum system and has been applied to a wide range of problems in quantum physics. We study a binary quantum control optimization problem, where control decisions…

Quantum Physics · Physics 2024-10-15 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

Quantum sensing exploits fundamental features of quantum system to achieve highly efficient measurement of physical quantities. Here, we propose a strategy to realize a single-qubit pseudo-Hermitian sensor from a dilated two-qubit Hermitian…

Quantum Physics · Physics 2020-01-22 Yaoming Chu , Yu Liu , Haibin Liu , Jianming Cai

The Nitrogen-Vacancy (NV) defect in diamond is a unique quantum system that offers precision sensing of nanoscale physical quantities beyond the current state-of-the-art. Here we present a method to controllably encode the interactions in…

Quantum control for error correction is critical for the practical use of quantum computers. We address quantum optimal control for single-shot multi-qubit gates by framing as a feasibility problem for the Hamiltonian model and then solving…

Quantum Physics · Physics 2019-05-07 Raymond J. Spiteri , Marina Schmidt , Joydip Ghosh , Ehsan Zahedinejad , Barry C. Sanders

A negatively charged nitrogen vacancy (NV) center in diamond has been recognized as a good solid-state qubit. A system consisting of the electronic spin of the NV center and hyperfine-coupled nitrogen and additionally nearby carbon nuclear…

Quantum Physics · Physics 2015-05-21 Yi Chou , Shang-Yu Huang , Hsi-Sheng Goan

We present a method for optimizing quantum control in experimental systems, using a subset of randomized benchmarking measurements to rapidly infer error. This is demonstrated to improve single- and two-qubit gates, minimize gate…

In this paper we formulate a risk-sensitive optimal control problem for continuously monitored open quantum systems modelled by quantum Langevin equations. The optimal controller is expressed in terms of a modified conditional state, which…

Quantum Physics · Physics 2016-09-08 M. R. James

Quantum technologies exploit entanglement to enhance various tasks beyond their classical limits including computation, communication and measurements. Quantum metrology aims to increase the precision of a measured quantity that is…

Quantum Physics · Physics 2020-08-25 Bálint Koczor , Suguru Endo , Tyson Jones , Yuichiro Matsuzaki , Simon C. Benjamin

During their operation, due to shifts in environmental conditions, devices undergo various forms of detuning from their optimal settings. Typically, this is addressed through control loops, which monitor variables and the device…

Quantum Physics · Physics 2024-04-17 T. Crosta , L. Rebón , F. Vilariño , J. M. Matera , M. Bilkis

We employ a quantum computer to simulate the effect of spin impurities on nitrogen-vacancy (NV) centers in diamond. As these defects operate as nanoscale quantum sensors, modeling quantum noise is crucial to identify limitations in…

Quantum Physics · Physics 2026-03-04 Alberto López-García , Aikaterini Vasilakou , Javier Cerrillo

Emerging reinforcement learning techniques using deep neural networks have shown great promise in control optimization. They harness non-local regularities of noisy control trajectories and facilitate transfer learning between tasks. To…

Quantum Physics · Physics 2018-04-17 Murphy Yuezhen Niu , Sergio Boixo , Vadim Smelyanskiy , Hartmut Neven

Quantum sensing has seen rapid progress from laboratory research to real-world applications. Solid-state spin systems, particularly nitrogen-vacancy (NV) centers in diamond, are attractive for their ability to operate at room temperature…

Quantum Physics · Physics 2025-07-22 Jonathan Kenny , Feifei Zhou , Ruihua He , Fedor Jelezko , Teck Seng Koh , Weibo Gao

The effectiveness of measurement-based feedback control (MBFC) protocols is hampered by the presence of measurement noise, which affects the ability to accurately infer the underlying dynamics of a quantum system from noisy continuous…

Quantum Physics · Physics 2023-11-23 Sangkha Borah , Bijita Sarma