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We investigate the fundamental limits in precision allowed by quantum mechanics from Landau-Zener transitions, concerning Hamiltonian parameters. While the Landau-Zener transition probabilities depend sensitively on the system parameters,…

Quantum Physics · Physics 2017-08-09 Jing Yang , Shengshi Pang , Andrew N. Jordan

We study the properties of optical pulse in cubic-quintic nonlinear media using information theoretic approach. The system can support regular (sharp top) and flat top pulse depending on the type of quintic interaction and the frequency of…

Pattern Formation and Solitons · Physics 2023-08-24 Bijan Layek , Sk. Siddik , Golam Ali Sekh

We study the problem of Quantum Likelihood Operators (LO) and their connection with quantum Fisher information (QFI). It is observed that the present approaches to this problem tacitly assume commutativity of parametrised density matrix…

Quantum Physics · Physics 2025-02-28 Kalyan B. Sinha , Ritabrata Sengupta

Based on the recent twisting-tensor approach [T. Opatrny, ArXiv:1408.3265 (2014)], a specific scenario for fast and deep spin squeezing is proposed. Initially the state is subjected to one-axis twisting under optimum orientation, enabling…

Quantum Physics · Physics 2014-09-03 Tomas Opatrny

We study information theoretic geometry in time dependent quantum mechanical systems. First, we discuss global properties of the parameter manifold for two level systems exemplified by i) Rabi oscillations and ii) quenching dynamics of the…

Statistical Mechanics · Physics 2016-05-05 Anshuman Dey , Suvankar Paul , Pratim Roy , Tapobrata Sarkar

Spin squeezing plays a crucial role in quantum metrology and quantum information science. Its generation is the prerequisite for further applications but still faces an enormous challenge since the existing physical systems rarely contain…

Quantum Physics · Physics 2023-11-09 Long-Gang Huang , Xuanchen Zhang , Yanzhen Wang , Zhenxing Hua , Yuanjiang Tang , Yong-Chun Liu

As a crucial resource in the field of quantum metrology, spin squeezing can facilitate highly precise measurements that surpass the limitations imposed by classical physics. However, the quantum advantage of spin squeezing is significantly…

Quantum Physics · Physics 2026-05-13 Lin Jiao , Han Pu , Jun-Hong An

Quantum Fisher information matrices (QFIMs) are fundamental to estimation theory: they encode the ultimate limit for the sensitivity with which a set of parameters can be estimated using a given probe. Since the limit invokes the inverse of…

Quantum Physics · Physics 2022-09-16 Aaron Z. Goldberg , José L. Romero , Ángel S. Sanz , Luis L. Sánchez-Soto

Recent advancements have revealed new links between information geometry and classical stochastic thermodynamics, particularly through the Fisher information (FI) with respect to time. Recognizing the non-uniqueness of the quantum Fisher…

Quantum Physics · Physics 2025-10-07 Laetitia P. Bettmann , John Goold

We address metrological protocols for the estimation of the intensity and the orientation of a magnetic field, and show that quantum-enhanced precision may be achieved by probing the field with an arbitrary spin at thermal equilibrium. We…

Quantum Physics · Physics 2018-07-04 Filippo Troiani , Matteo G. A. Paris

Quantum Fisher Information (QFI) is a measure quantifying the sensitivity of a quantum state with respect to changes in tuning parameters in quantum metrology, and defining quantum speed limits. We show that even if the quantum state is…

Quantum Physics · Physics 2025-07-23 Alexander Kruchkov

We study the changes in quantum Fisher information (QFI) values for one quantum system consisting of a superposition of W and GHZ states. In a recent work [6], QFI values of this mentioned system studied. In this work, we extend this…

Quantum Physics · Physics 2017-04-26 Volkan Erol

We develop a Bloch vector representation of Unruh channel for a Dirac field mode. This is used to provide a unified, analytical treatment of quantum Fisher and Skew information for a qubit subjected to the Unruh channel, both in its pure…

Quantum Physics · Physics 2016-08-09 Subhashish Banerjee , Ashutosh Kumar Alok , S. Omkar

We calculate the spin dependent Fermi liquid parameters (FLPs), single particle energies and energy densities of various spin states of polarized quark matter. The expressions for the incompressibility($K$) and sound velocity ($c_1$) in…

High Energy Physics - Phenomenology · Physics 2009-01-28 Kausik Pal , Subhrajyoti Biswas , Abhee K. Dutt-Mazumder

Multi-mode squeezing and entanglement are important resources in quantum metrology and sensing. For spin-1/2 Bose-Einstein condensates subject to spin-orbit coupling (SOC), previous studies on spin squeezing have been limited to two-mode…

Quantum Gases · Physics 2025-08-07 Fei Zhu , Zheng Tang , Liang Zeng , Shu Wang , Li Chen

The Fisher information of a quantum observable is shown to be proportional to both (i) the difference of a quantum and a classical variance, thus providing a measure of nonclassicality; and (ii) the rate of entropy increase under Gaussian…

Quantum Physics · Physics 2009-10-31 Michael J. W. Hall

A spin system on a lattice can usually be modelled at large scales by an effective quantum field theory. A key mathematical result relating the two descriptions is the quantum central limit theorem, which shows that certain spin observables…

Quantum Physics · Physics 2017-01-20 Cédric Bény

quantum theory of generalized $\mathrm{X}$ waves with orbital angular momentum in dispersive media, and the interaction of quantized $\mathrm{X}$ waves in quadratic nonlinear media were studied in (J. opt,20,065201(2018)). We present a kind…

Quantum Physics · Physics 2020-08-26 Ali Saif M. Hassan , Waleed S. A. Hasan , M. A. Shukri

Precision measurements with quantum systems rely on our ability to trace the differences between experimental signals to variations in unknown physical parameters. In this Letter we derive the Fisher information and the ensuing Cramer-Rao…

Quantum Physics · Physics 2015-06-17 Søren Gammelmark , Klaus Mølmer

We consider an antiferromagnetic Bose-Einstein condensate in a traverse magnetic field with a fixed macroscopic magnetization. The system exhibits two different critical behaviors corresponding to transitions from polar to…

Quantum Gases · Physics 2020-05-07 Safoura S. Mirkhalaf , Emilia Witkowska , Luca Lepori