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Related papers: Optimal Control and Glassiness in Quantum Sensing

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Entanglement generation can be robust against noise in approaches that deliberately incorporate dissipation into the system dynamics. The presence of additional dissipation channels may, however, limit fidelity and speed of the process.…

Quantum Physics · Physics 2019-01-28 Karl P. Horn , Florentin Reiter , Yiheng Lin , Dietrich Leibfried , Christiane P. Koch

We experimentally study the time-optimal construction of arbitrary single-qubit rotations under a single strong driving field of finite amplitude. Using radiation-dressed states of nitrogen vacancy centers in diamond, we realize a…

Quantum Physics · Physics 2014-07-02 Chen Avinadav , Ran Fischer , Paz London , David Gershoni

Over the years, an enormous effort has been made to establish nitrogen vacancy (NV) centers in diamond as easily accessible and precise magnetic field sensors. However, most of their sensing protocols rely on the application of bias…

A pivotal task in quantum metrology, and quantum parameter estimation in general, is to de- sign schemes that achieve the highest precision with given resources. Standard models of quantum metrology usually assume the dynamics is fixed, the…

Quantum Physics · Physics 2017-07-18 Jing Liu , Haidong Yuan

The accumulation of quantum phase in response to a signal is the central mechanism of quantum sensing, as such, loss of phase information presents a fundamental limitation. For this reason approaches to extend quantum coherence in the…

Quantum sensing is one of the key areas which exemplifies the superiority of quantum technologies. Nonetheless, most quantum sensing protocols operate efficiently only when the unknown parameters vary within a very narrow region, i.e.,…

Quantum Physics · Physics 2021-05-26 Victor Montenegro , Utkarsh Mishra , Abolfazl Bayat

In this work, we extend the quantum optimal control theory of molecules subject to ultrashort laser pulses to the case of solvated systems, explicitly including the solvent dielectric properties in the system Hamiltonian. A reliable…

Chemical Physics · Physics 2019-12-23 Marta Rosa , Gabriel Gil , Stefano Corni , Roberto Cammi

Quantum resources can enhance the sensitivity of a device beyond the classical shot noise limit and, as a result, revolutionize the field of metrology through the development of quantum-enhanced sensors. In particular, plasmonic sensors,…

Most quantum processors requires pulse sequences for controlling quantum states. Here, we present an alternative algorithm for computing an optimal pulse sequence in order to perform a specific task, being an implementation of a quantum…

Quantum Physics · Physics 2020-05-27 John P. S. Peterson , Roberto S. Sarthour , Raymond Laflamme

We demonstrate quantum logic enhanced sensitivity for a macroscopic ensemble of solid-state, hybrid two-qubit sensors. We achieve a factor of 30 improvement in signal-to-noise ratio, translating to a sensitivity enhancement exceeding an…

For quantum systems with high purity, we find all observables that, when continuously monitored, maximize the instantaneous reduction in the von Neumann entropy. This allows us to obtain all locally optimal feedback protocols with strong…

Quantum Physics · Physics 2009-11-13 Alireza Shabani , Kurt Jacobs

Nitrogen vacancy (NV) centers in diamond are widely deployed as local magnetic sensors, using coherent, single qubit control to measure both time-averaged fields and noise with nanoscale spatial resolution. Moving beyond single qubits to…

Quantum Physics · Physics 2025-04-18 Jared Rovny , Shimon Kolkowitz , Nathalie P. de Leon

Achieving high-fidelity control of quantum systems is of fundamental importance in physics, chemistry and quantum information sciences. However, the successful implementation of a high-fidelity quantum control scheme also requires…

Quantum Physics · Physics 2018-06-05 Yu Guo , Daoyi Dong , Chuan-Cun Shu

Feedback control of quantum systems via continuous measurement involves complex nonlinear dynamics. Except in very special cases, even for a single qubit optimal feedback protocols are unknown. Not even do intuitive candidates exist for…

Quantum Physics · Physics 2015-07-30 Ashkan Balouchi , Kurt Jacobs

Experiments in coherent spectroscopy correspond to control of quantum mechanical ensembles guiding them from initial to final target states. The control inputs (pulse sequences) that accomplish these transformations should be designed to…

Quantum Physics · Physics 2009-11-07 Navin Khaneja , Timo Reiss , Burkhard Luy , Steffen J. Glaser

Robust and high-fidelity control of electron spins in solids is the cornerstone for facilitating applications of solid-state spins in quantum information processing and quantum sensing. However, precise control of spin systems is always…

Quantum Physics · Physics 2022-05-06 Yifan Zhang , Hao Wu , Xiaodong Yang , Ye-Xin Wang , Chang Liu , Qing Zhao , Jiyang Ma , Jun Li , Bo Zhang

Quantum computation provides great speedup over its classical counterpart for certain problems. One of the key challenges for quantum computation is to realize precise control of the quantum system in the presence of noise. Control of the…

Quantum Physics · Physics 2015-11-30 Xing Rong , Jianpei Geng , Fazhan Shi , Ying Liu , Kebiao Xu , Wenchao Ma , Fei Kong , Zhen Jiang , Yang Wu , Jiangfeng Du

Quantum sensing is an important application of emerging quantum technologies. We explore whether a hybrid system of quantum sensors and quantum circuits can surpass the classical limit of sensing. In particular, we use optimization…

Spin degrees of freedom of charged nitrogen-vacancy (NV$^-$) centers in diamond have large decoherence times even at room temperature, can be initialized and read out using optical fields, and are therefore a promising candidate for solid…

Other Condensed Matter · Physics 2009-11-13 A. M. Zagoskin , J. R. Johansson , S. Ashhab , Franco Nori

Motivated by some recent results of quantum control theory, we discuss the feasibility of local operator control in arrays of interacting qubits modeled as isotropic Heisenberg spin chains. Acting on one of the end spins, we aim at finding…

Quantum Physics · Physics 2018-11-13 Rahel Heule , C. Bruder , Daniel Burgarth , Vladimir M. Stojanovic