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Related papers: Indefinite Time Directed Quantum Metrology

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Critical quantum metrology aims to harness critical properties near quantum phase transitions to enhance parameter estimation precision. However, critical slowing down inherently limits the achievable precision within a finite evolution…

Quantum Physics · Physics 2025-06-25 Ju-Yeon Gyhm , Hyukjoon Kwon , Myung-Joong Hwang

We consider the continuous-time version of our recently proposed quantum theory of optical temporal phase and instantaneous frequency [Tsang, Shapiro, and Lloyd, Phys. Rev. A 78, 053820 (2008)]. Using a state-variable approach to…

Quantum Physics · Physics 2009-05-21 Mankei Tsang , Jeffrey H. Shapiro , Seth Lloyd

We propose an $N$-photon Gaussian measurement scheme which allows the estimation of a parameter $\varphi$ encoded into a multi-port interferometer with a Heisenberg scaling precision (i.e. of order $1/N$). In this protocol, no restrictions…

Quantum Physics · Physics 2021-12-23 Giovanni Gramegna , Danilo Triggiani , Paolo Facchi , Frank A. Narducci , Vincenzo Tamma

We show how quantum metrology protocols that seek to estimate the parameters of a Hamiltonian that exhibits a quantum phase transition can be efficiently simulated on an exponentially smaller quantum computer. Specifically, by exploiting…

Quantum Physics · Physics 2016-12-28 W. L. Boyajian , M. Skotiniotis , W. Dür , B. Kraus

The standard quantum formalism introduced at the undergraduate level treats measurement as an instantaneous collapse. In reality however, no physical process can occur over a truly infinitesimal time interval. A more subtle investigation of…

Quantum Physics · Physics 2020-04-22 Leigh S. Martin

We propose a measurement setup reaching Heisenberg scaling precision for the estimation of any distributed parameter $\varphi$ (not necessarily a phase) encoded into a generic $M$-port linear network composed only of passive elements. The…

Quantum Physics · Physics 2021-12-23 Giovanni Gramegna , Danilo Triggiani , Paolo Facchi , Frank A. Narducci , Vincenzo Tamma

Standard quantum mechanics is an idealisation based on infinite-precision objects: point states, exact probabilities, and sharp measurements. Yet every real experiment has finite resolution, and for macroscopic systems we never have access…

Quantum Physics · Physics 2026-05-29 Abbas Edalat

The Quantum Fisher Information (QFI) is a geometric measure of state deformation calculated along the trajectory parameterizing an ensemble of quantum states. It serves as a key concept in quantum metrology, where it is linked to the…

Quantum Physics · Physics 2025-12-05 Gabriela Wójtowicz , Susana F. Huelga , Marek M. Rams , Martin B. Plenio

We derive a necessary and sufficient condition for the possibility of achieving the Heisenberg scaling in general adaptive multi-parameter estimation schemes in presence of Markovian noise. In situations where the Heisenberg scaling is…

Quantum Physics · Physics 2020-07-08 Wojciech Gorecki , Sisi Zhou , Liang Jiang , Rafal Demkowicz-Dobrzanski

Despite the numerous uses of semidefinite programming (SDP) and its universal solvability via interior point methods (IPMs), it is rarely applied to practical large-scale problems. This mainly owes to the computational cost of IPMs that…

Optimization and Control · Mathematics 2024-03-19 Yifan Ran , Stefan Vlaski , Wei Dai

We study the role of the electromagnetic field's frequency in time precision measurements using single photons as a paradigmatic system. For such, we independently identify the contributions of intensity and spectral resources and show that…

Quantum Physics · Physics 2024-12-09 Eloi Descamps , Nicolas Fabre , Arne Keller , Perola Milman

Quantum Fisher information matrix (QFIM) is a core concept in theoretical quantum metrology due to the significant importance of quantum Cram\'{e}r-Rao bound in quantum parameter estimation. However, studies in recent years have revealed…

Quantum Physics · Physics 2020-03-27 Jing Liu , Haidong Yuan , Xiao-Ming Lu , Xiaoguang Wang

We propose a spin-motion state for high-precision quantum metrology with super-Heisenberg scaling of the parameter estimation uncertainty using a trapped ion system. Such a highly entangled state can be created using the Tavis-Cummings…

Quantum Physics · Physics 2024-11-18 Venelin P. Pavlov , Peter A. Ivanov

Phase estimation with potentially large phase values, i.e., with large dynamic range, has many applications in quantum metrology, for example to atomic clocks. A recently proposed phase estimation scheme approaches the Heisenberg scaling in…

Quantum Physics · Physics 2026-03-17 Tyler G. Thurtell , Akimasa Miyake

Quantum computing and quantum sensing represent two distinct frontiers of quantum information science. In this work, we harness quantum computing to solve a fundamental and practically important sensing problem: the detection of weak…

Quantum Physics · Physics 2025-01-15 Richard R. Allen , Francisco Machado , Isaac L. Chuang , Hsin-Yuan Huang , Soonwon Choi

Discrete time crystals are non-equilibrium phases of matter in periodically driven systems, characterized by robust subharmonic oscillations and broken discrete time-translation symmetry. Their long-lived coherent dynamics and resilience to…

Quantum Physics · Physics 2026-04-29 Rozhin Yousefjani , Shaikha Al-Naimi , Saif Al-Kuwari , Abolfazl Bayat

Precise estimation of physical parameters underpins both scientific discovery and technological development. A central goal of quantum metrology and sensing is to exploit quantum resources like entanglement to devise optimal strategies for…

Quantum Physics · Physics 2026-03-09 Zhao-Yi Zhou , Da-Jian Zhang

Quantum criticality of open many-body systems has attracted lots of interest for emergent phenomena and universality. Here we present the exact steady state of the quantum van der Pol oscillator using the complex $P$-representation. We show…

Quantum Physics · Physics 2025-09-03 Yaohua Li , Xuanchen Zhang , Yong-Chun Liu

We propose a class of metrological resource states whose quantum Fisher information scales optimally in both system size and noise rate. In these states, qubits are partitioned into sensing groups with relatively large correlations within a…

Quantum Physics · Physics 2026-04-01 Chao Yin , Victor V. Albert , Sisi Zhou

The number of times that we can access a system to extract information via quantum metrology is always finite, and possibly small, and realistic amounts of prior knowledge tend to be moderate. Thus theoretical consistency demands a…

Quantum Physics · Physics 2021-12-02 Jesús Rubio