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Related papers: Frequency estimation by frequency jumps

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We have derived explicit non-perturbative expression for decoherence of quantum oscillations in a qubit by low-frequency noise. Decoherence strength is controlled by the noise spectral density at zero frequency while the noise correlation…

Superconductivity · Physics 2009-11-10 K. Rabenstein , V. A. Sverdlov , D. V. Averin

Ramsey interferometry is a widely used tool for precisely measuring transition frequencies between two energy levels of a quantum system, with applications in time-keeping, precision spectroscopy, quantum optics, and quantum information.…

Quantum Physics · Physics 2023-02-21 H. Hainzer , D. Kiesenhofer , T. Ollikainen , M. Bock , F. Kranzl , M. K. Joshi , G. Yoeli , R. Blatt , T. Gefen , C. F. Roos

Squeezing of quantum fluctuations by means of entanglement is a well recognized goal in the field of quantum information science and precision measurements. In particular, squeezing the fluctuations via entanglement between two-level atoms…

Quantum Physics · Physics 2009-11-25 J. Appel , P. J. Windpassinger , D. Oblak , U. B. Hoff , N. Kjaergaard , E. S. Polzik

We present a general and exact formalism for finding the evolution of a quantum system subject to external telegraph noise. The various qubit decoherence rates are determined by the eigenvalues of a transfer matrix. The formalism can be…

Quantum Physics · Physics 2009-11-13 Bin Cheng , Qiang-Hua Wang , Robert Joynt

Non-conventional receivers for phase-coherent states based on non-Gaussian measurements such as photon counting surpass the sensitivity limits of shot-noise-limited coherent receivers, the quantum noise limit (QNL). These non-Gaussian…

Quantum Physics · Physics 2020-07-07 M. T. DiMario , F. E. Becerra

A quantum trajectory describes the evolution of a quantum system undergoing indirect measurement. In the discrete-time setting, the state of the system is updated by applying Kraus operators according to the measurement results. From an…

Quantum Physics · Physics 2022-04-04 Maël Bompais , Nina H. Amini , Clément Pellegrini

We study the evolution of a trapped atomic cloud subject to a trapping frequency jump for two cases: stationary and moving center of mass. In the first case, the frequency jump initiates oscillations in the cloud's momentum and size. At…

Atomic Physics · Physics 2009-11-11 P Ahmadi , G Behinaein , B P Timmons , G S Summy

Extracting energy spectra from quantum Hamiltonians is a fundamental task for quantum simulation, yet remains challenging on noisy intermediate-scale quantum (NISQ) devices. We propose Measured Quantum Time Evolution (MQTE), an ancilla-free…

Quantum Physics · Physics 2026-03-19 Qing-Xing Xie , Yong-Kang Duan , Fa-Hui Liu , Yan Zhao

High-precision frequency estimation is an ubiquitous issue in fundamental physics and a critical task in spectroscopy. Here, we propose a quantum Ramsey interferometry to realize high-precision frequency estimation in spin-1 Bose-Einstein…

Quantum Physics · Physics 2021-09-06 Min Zhuang , Hongtao Huo , Yuxiang Qiu , Wenjie Liu , Jiahao Huang , Chaohong Lee

Current approaches to fault-tolerant quantum computation will not enable useful quantum computation on near-term devices of 50 to 100 qubits. Leading proposals, such as the color code and surface code schemes, must devote a large fraction…

Quantum Physics · Physics 2017-11-08 Peter D. Johnson , Jonathan Romero , Jonathan Olson , Yudong Cao , Alán Aspuru-Guzik

In this paper, we propose a scheme to eliminate the influence of noises on system dynamics, by means of a sequential unsharp measurements and unitary feedback operations. The unsharp measurements are carried out periodically during system…

Quantum Physics · Physics 2018-09-19 Du Ran , Ye-Hong Chen , Zhi-Cheng Shi , Zhen-Biao Yang , Jie Song , Yan Xia

System noise identification is crucial to the engineering of robust quantum systems. Although existing quantum noise spectroscopy (QNS) protocols measure an aggregate amount of noise affecting a quantum system, they generally cannot…

The estimation of parameters characterizing dynamical processes is central to science and technology. The estimation error changes with the number N of resources employed in the experiment (which could quantify, for instance, the number of…

Quantum Physics · Physics 2012-01-10 B. M. Escher , R. L. de Matos Filho , L. Davidovich

Extracting the outcome of a quantum computation is a difficult task. In many cases, the quantum phase estimation algorithm is used to digitally encode a value in a quantum register whose amplitudes' magnitudes reflect the discrete sinc…

Quantum Physics · Physics 2022-07-04 Charlee Stefanski , Vanio Markov , Constantin Gonciulea

A parametrically driven classical harmonic oscillator exhibits resonant instability when driven at twice its natural frequency, with the lowest energy configuration remaining unaffected by the drive. In contrast, the ground state of the…

Quantum Physics · Physics 2026-05-27 Ranjani Seshadri

Hybrid systems consisting of a quantum emitter coupled to a mechanical oscillator are receiving increasing attention for fundamental science and potential applications in quantum technologies. In contrast to most of the presented works, in…

Information-theoretically provable unique true random numbers, which cannot be correlated or controlled by an attacker, can be generated based on quantum measurement of vacuum state and universal-hashing randomness extraction. Quantum…

Quantum Physics · Physics 2018-11-14 Xiaomin Guo , Ripeng Liu , Pu Li , Chen Cheng , Mingchuan Wu , Yanqiang Guo

The recently introduced detected-jump correcting quantum codes are capable of stabilizing qubit-systems against spontaneous decay processes arising from couplings to statistically independent reservoirs. These embedded quantum codes exploit…

Quantum Physics · Physics 2011-03-31 G. Alber , Th. Beth , Ch. Charnes , A. Delgado , M. Grassl , M. Mussinger

Interactions among sensors can provide, in addition to entanglement, an important resource for boosting the precision in quantum estimation protocols. Dephasing noise, however, remains a leading source of decoherence in state-of-the-art…

Quantum Physics · Physics 2025-01-03 Francisco Riberi , Lorenza Viola

We use the theory of quantum estimation in two different qubit-boson coupling models to demonstrate that the temperature of a quantum harmonic oscillator can be estimated with high precision by quantum-limited measurements on the qubit. The…

Quantum Physics · Physics 2012-10-31 Matteo Brunelli , Stefano Olivares , Mauro Paternostro , Matteo G. A. Paris
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