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Related papers: Dynamic framework for criticality-enhanced quantum…

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The metrological limits of thermometry operated in nonequilibrium dynamical regimes are analyzed. We consider a finite-dimensional quantum system, employed as a quantum thermometer, in contact with a thermal bath inducing Markovian…

There is a prevalent effort to achieve quantum-enhanced metrology using criticality. However, the extent to which estimation precision is enhanced through criticality still needs further exploration under the constraint of finite time…

Quantum Physics · Physics 2024-07-31 Rui Zhang , Wenkui Ding , Zhucheng Zhang , Lei Shao , Yuyu Zhang , Xiaoguang Wang

Characterizing quantum critical states towards the thermodynamic limit is essential for understanding phases of matter. The power of quantum simulators for preparing the critical states relies crucially on the structure of quantum circuits…

Quantum Physics · Physics 2026-03-31 Mei Peng , Xu-Dan Xie , Dan-Bo Zhang

The physics of quantum states beyond thermodynamic equilibrium represents a fascinating and cutting-edge research. Using numerical state-of-the-art approaches, we observe dynamical quantum phase transitions in the dissipative two-qubit Rabi…

Quantum Physics · Physics 2025-09-08 G. Di Bello , A. Ponticelli , F. Pavan , V. Cataudella , G. De Filippis , A. de Candia , C. A. Perroni

There has been debate around applicability of exceptional points (EP) for quantum sensing. To resolve this, we first explore how to experimentally implement the nonhermitian non-diagonalizable Hamiltonians, that exhibit EPs, in quantum…

Quantum Physics · Physics 2024-01-15 Chetan Waghela , Shubhrangshu Dasgupta

The quantum Rabi model (QRM) is a fundamental model for light-matter interactions. A fascinating feature of the QRM is that it manifests a quantum phase transition which is applicable for critical quantum metrology (CQM). Effective…

Quantum Physics · Physics 2024-09-20 Zu-Jian Ying , Wen-Long Wang , Bo-Jian Li

The quantum Fisher information (QFI) associated with a particular process applied to a many-body quantum system has been suggested as a diagnostic for the nature of the system's quantum state, e.g., a thermal density matrix vs. a pure state…

Statistical Mechanics · Physics 2023-04-05 Fernando Iniguez , Mark Srednicki

Estimating a classical parameter encoded in the Hamiltonian of a quantum probe is a fundamental and well-understood task in quantum metrology. A textbook example is the estimation of a classical field's amplitude using a two-level probe, as…

Quantum Physics · Physics 2026-04-15 Ricard Ravell Rodríguez , Martí Perarnau-Llobet , Pavel Sekatski

We introduce a first-order quantum-phase-transition model, which exhibits giant sensitivity $\chi \propto N^2$ at the critical point. Exploiting this effect, we propose a quantum critical detector (QCD) to amplify weak input signals. The…

Quantum Physics · Physics 2019-04-03 Li-Ping Yang , Zubin Jacob

The characterization of entanglement is a central problem for the study of quantum many-body dynamics. Here, we propose the quantum Fisher information as a useful tool for the study of multipartite-entanglement dynamics in many-body…

Statistical Mechanics · Physics 2019-02-27 Karol Gietka , Jan Chwedeńczuk , Tomasz Wasak , Francesco Piazza

We carefully examine critical metrology and present an improved critical quantum metrology protocol which relies on quenching a system exhibiting a superradiant quantum phase transition beyond its critical point. We show that this approach…

Quantum Physics · Physics 2022-05-04 Karol Gietka , Lewis Ruks , Thomas Busch

Critical systems represent a valuable resource in quantum sensing and metrology. Critical quantum sensing (CQS) protocols can be realized using finite-component phase transitions, where criticality arises from the rescaling of system…

Quantum Physics · Physics 2025-04-15 Uesli Alushi , Alessandro Coppo , Valentina Brosco , Roberto Di Candia , Simone Felicetti

Critical metrology relies on the precise preparation of a system in its ground state near a quantum phase transition point where quantum correlations get very strong. Typically this increases the quantum Fisher information with respect to…

Quantum Physics · Physics 2024-02-12 Christoph Hotter , Helmut Ritsch , Karol Gietka

Quantum phase transitions occur when the ground state of a quantum system undergoes a qualitative change when an external control parameter reaches a critical value. Here, we demonstrate a technique for studying quantum systems undergoing a…

Quantum Physics · Physics 2008-03-14 Jingfu Zhang , Xinhua Peng , Nageswaran Rajendran , Dieter Suter

Established methods for characterizing quantum information processes do not capture non-Markovian (history-dependent) behaviors that occur in real systems. These methods model a quantum process as a fixed map on the state space of a…

Quantum Physics · Physics 2019-09-04 Ryan S. Bennink , Pavel Lougovski

Critical quantum systems are a promising resource for quantum metrology applications, due to the diverging susceptibility developed in proximity of phase transitions. Here, we assess the metrological power of parametric Kerr resonators…

Quantum Physics · Physics 2023-03-30 R. Di Candia , F. Minganti , K. V. Petrovnin , G. S. Paraoanu , S. Felicetti

We present the experimental measurement, on a quantum processor, of a series of polynomial lower bounds that converge to the quantum Fisher information (QFI), a fundamental quantity for certifying multipartite entanglement that is useful…

This work unifies the equilibrium and non-equilibrium frameworks of quantum metrology within the context of many-body systems. We investigate dynamic sensing schemes to derive an upper bound on the quantum Fisher information for probe…

Quantum Physics · Physics 2025-12-03 Rui Zhang , Yang Yang , Wenkui Ding , Xiaoguang Wang

By using the quantum Yang-Baxterization approach to the three different Hamiltonians, we investigate the behavior of the quantum Fisher information (QFI) under the actions of these Hamiltonians on the different two-qubit input states and by…

Quantum Physics · Physics 2020-08-27 Durgun Duran

The quantum to classical transition (QCT) is one of the central mysteries in quantum physics. This process is generally interpreted as state collapse from measurement or decoherence from interacting with the environment. Here we define the…

Quantum Physics · Physics 2023-11-14 Wei-Feng Zhuang , Yun-Tong Yang , Hong-Gang Luo , Ming Gong , Guang-Can Guo