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Related papers: Quantum estimation in an expanding spacetime

200 papers

We discuss a parameter estimation problem using quantum decoherece in the double-slit interferometer. We consider a particle coupled to a massive scalar field after the particle passing through the double slit and solve the dynamics…

Quantum Physics · Physics 2018-07-18 Akira Matsumura , Taishi Ikeda , Shingo Kukita

We provide a general framework for handling the effects of a unitary disturbance on the estimation of the amplitude $\lambda$ associated to a unitary dynamics. By computing an analytical and general expression for the quantum Fisher…

Quantum Physics · Physics 2013-11-20 A. De Pasquale , D. Rossini , P. Facchi , V. Giovannetti

Quantum coherence in curved spacetime offers a fresh window into the interplay between gravity, thermality, and quantum resources. While previous work has shown that Markovian evolution can generate entanglement and other nonclassical…

General Relativity and Quantum Cosmology · Physics 2025-10-06 Samira Elghaayda , Atta ur Rahman , Mostafa Mansour

We address the scattering of a quantum particle by a one-dimensional barrier potential over a set of discrete positions. We formalize the problem as a continuous-time quantum walk on a lattice with an impurity, and use the quantum Fisher…

Quantum Physics · Physics 2020-12-30 Francesco Zatelli , Claudia Benedetti , Matteo G. A. Paris

The decay rate of the Bunch-Davies state of a massive scalar field in the expanding flat spatial sections of de Sitter space is determined by an analysis of the particle pair creation process in real time. The Feynman definition of particle…

General Relativity and Quantum Cosmology · Physics 2018-04-04 Paul R. Anderson , Emil Mottola , Dillon H. Sanders

The Heisenberg limit provides a fundamental bound on the achievable estimation precision with a limited number of $N$ resources used (e.g., atoms, photons, etc.). Using entangled quantum states makes it possible to scale the precision with…

Quantum Physics · Physics 2023-04-28 Wojciech Górecki

We present a proof-of-principle study of variational quantum sensing for estimating a structured linear function of local phase parameters, in which each qubit in a spin-1/2 array accumulates a phase phi_i = alpha_i theta with known weights…

Quantum Physics · Physics 2026-05-19 Priyam Srivastava , Vivek Kumar , Gurudev Dutt , Kaushik P. Seshadreesan

The formalism of quantum estimation theory is applied to estimate the disorders in the positions of two membranes positioned in a driven cavity. We consider the coupled-cavities and the transmissive-regime models to obtain effective…

Quantum Physics · Physics 2024-06-04 Claudio Sanavio , József Zsolt Bernád , André Xuereb

We describe inflation in terms of a time dependent quantum density matrix with time playing the role of a stochastic variable. Using a quasi-de Sitter model we compute the corresponding quantum Fisher information function as the second…

High Energy Physics - Theory · Physics 2020-09-16 Cesar Gomez , Raul Jimenez

Recently, there is a growing interest in study quantum mechanics from the information geometry perspective, where a quantum state is depicted with a point in the projective Hilbert space. By taking quantum Fisher information (QFI) as the…

Quantum Physics · Physics 2021-01-04 Haijun Xing , Libin Fu

We consider estimating the magnitude of a monochromatic AC signal that couples to a two-level sensor. For any detection protocol, the precision achieved depends on the signal's frequency and can be quantified by the quantum Fisher…

We investigate quantum phase estimation in a Mach-Zehnder interferometer using q-deformed photon states, including q-coherent and q-cat states, which model realistic deviations from ideal light sources. By deriving closed-form photon count…

Quantum Physics · Physics 2025-10-07 Duttatreya , Sanjib Dey

We address the problem of estimating the mass of a quantum particle in a gravitational field and seek the ultimate bounds to precision of quantum-limited detection schemes. In particular, we study the effect of the field on the achievable…

General Relativity and Quantum Cosmology · Physics 2017-05-24 Luigi Seveso , Valerio Peri , Matteo G. A. Paris

Small, controllable quantum systems, known as quantum probes, have been proposed to estimate various parameters characterizing complex systems such as the environments of quantum systems. These probes, prepared in some initial state, are…

Quantum Physics · Physics 2021-07-21 Hamza Ather , Adam Zaman Chaudhry

By using the non-Markovian master equation, we investigate the effect of the cavity and the environment on the quantum Fisher information (QFI) of an atom qubit system in a dissipation cavity. We obtain the formulae of QFI for two different…

Quantum Physics · Physics 2019-05-17 Danping Lin , Yu Liu , Hong-Mei Zou

Quantum metrology concerns improving the estimation of an unknown parameter using an optimal measurement scheme on the quantum system. More the optimality of the measurement, the better will be the improvement in sensing the value of the…

Quantum Physics · Physics 2025-07-30 H. S. Karthik

We give an interpretation of the temperature in de Sitter universe in terms of a dynamical Unruh effect associated with the Hubble sphere. As with the quantum noise perceived by a uniformly accelerated observer in static space-times,…

General Relativity and Quantum Cosmology · Physics 2011-09-23 R. Casadio , S. Chiodini , A. Orlandi , G. Acquaviva , R. Di Criscienzo , L. Vanzo

Probing quantumness in curved spacetime is regarded as one of fundamental and important topics in the framework of relativistic quantum information. In this work, we focus on the theoretical feasibility of probing quantum properties in de…

High Energy Physics - Theory · Physics 2025-03-05 Li-Juan Li , Xue-Ke Song , Liu Ye , Dong Wang

We study the role of quantum entanglement (particle entanglement and mode entanglement) in optical phase estimation by employing the first and second quantization formalisms of quantum mechanics. The quantum Fisher information (QFI) is…

Quantum Physics · Physics 2016-09-23 Jaspreet Sahota , Nicolás Quesada , Daniel F. V. James

We study the quantum correlation and quantum communication channel of both free scalar and fermionic fields in de Sitter space, while the Planckian modification presented by the choice of a particular $\alpha$-vacuum has been considered. We…

Quantum Physics · Physics 2014-11-18 Jun Feng , Yao-Zhong Zhang , Mark D. Gould , Heng Fan , Cheng-Yi Sun , Wen-Li Yang