English
Related papers

Related papers: Quantum probes for quantum wells

200 papers

Quantum entanglement is a resource in quantum metrology that can be distributed to two orthogonal physical quantities for the enhancement of their joint measurement sensitivity, as demonstrated in quantum dense metrology. On the other hand,…

Quantum Physics · Physics 2019-04-11 Yuhong Liu , Nan Huo , Jiamin Li , Liang Cui , Xiaoying Li , Z. Y. Ou

We investigate strategies for estimating a depolarizing channel for a finite dimensional system. Our analysis addresses the double optimization problem of selecting the best input probe state and the measurement strategy that minimizes the…

Quantum Physics · Physics 2009-11-07 Masahide Sasaki , Masashi Ban , Stephen M. Barnett

We introduce a resource monotone, the completeness stability, to quantify the quality of quantum measurements within a resource-theoretic framework. By viewing a quantum measurement as a frame, the minimum eigenvalue of a frame operator…

Quantum Physics · Physics 2026-01-21 Rakesh Saini , Jukka Kiukas , Daniel Burgarth , Alexei Gilchrist

Motivated by the limited understanding of entanglement entropy in non-asymptotically AdS spacetimes, we develop a framework in which a circular string is embedded as a quantum probe in a spherically symmetric curved spacetime, and its…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Ai-chen Li , Xin-Fei Li , Xuanting Ji

Estimation of physical observables for unknown quantum states is an important problem that underlies a wide range of fields, including quantum information processing, quantum physics, and quantum chemistry. In the context of quantum…

Quantum Physics · Physics 2024-05-21 Yuma Nakamura , Yoshichika Yano , Nobuyuki Yoshioka

To establish an entangled state of optimal fidelity between two distant observers when the available quantum channel is noisy, is a central problem in quantum information theory. We consider an instance of this problem for two-qubit systems…

Quantum Physics · Physics 2012-09-18 Somshubhro Bandyopadhyay , Anindita Ghosh

Network Utility Maximisation (NUM) addresses the problem of allocating resources fairly within a network and explores the ways to achieve optimal allocation in real-world networks. Although extensively studied in classical networks, NUM is…

Networking and Internet Architecture · Computer Science 2024-07-25 Sounak Kar , Stephanie Wehner

Quantum scale estimation, as introduced and explored here, establishes the most precise framework for the estimation of scale parameters that is allowed by the laws of quantum mechanics. This addresses an important gap in quantum metrology,…

Quantum Physics · Physics 2022-11-18 Jesús Rubio

Quantum sensing employs quantum resources of a sensor to attain a smaller estimation error of physical quantities than the limit constrained by classical physics. To measure a quantum reservoir, which is significant in decoherence control,…

Quantum Physics · Physics 2021-05-21 Wei Wu , Zhen Peng , Si-Yuan Bai , Jun-Hong An

Quantum metrology overcomes standard precision limits and plays a central role in science and technology. Practically it is vulnerable to imperfections such as decoherence. Here, we demonstrate quantum metrology for noisy channels such that…

Quantum Physics · Physics 2018-04-25 Kunkun Wang , Xiaoping Wang , Xiang Zhan , Zhihao Bian , Jian Li , Barry C. Sanders , Peng Xue

We investigate entanglement distribution in pure-state quantum networks. We consider the case when non-maximally entangled two-qubit pure states are shared by neighboring nodes of the network. For a given pair of nodes, we investigate how…

Quantum Physics · Physics 2009-01-19 S. Perseguers , J. Wehr , A. Acin , M. Lewenstein , J. I. Cirac

The advent of cloud quantum computing has led to the rapid development of quantum algorithms. In particular, it is necessary to study variational quantum-classical hybrid algorithms, which are executable on noisy intermediate-scale quantum…

Quantum Physics · Physics 2020-07-02 Ikko Hamamura , Takashi Imamichi

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 present an approach to purification and entanglement routing on complex quantum network architectures, that is, how a quantum network equipped with imperfect channel fidelities and limited memory storage time can distribute entanglement…

Dynamical response functions are fundamental quantities to describe the excited-state properties in quantum many-body systems. Quantum algorithms have been proposed to evaluate these quantities by means of quantum phase estimation (QPE),…

Quantum Physics · Physics 2024-08-27 Rei Sakuma , Shu Kanno , Kenji Sugisaki , Takashi Abe , Naoki Yamamoto

Quantum coherence and entanglement are fundamental resources in quantum technologies, yet their efficient estimation for unknown states by employing minimal resources in experimental settings remains challenging, particularly in…

Quantum Physics · Physics 2026-01-12 Ting Lin , Zhihua Chen , Kai Wu , Zhihua Guo , Zhihao Ma , Shao-Ming Fei

Quantum instruments describe both the classical outcome and the updated state associated with a quantum measurement. We ask whether these processes can be simulated using only a natural subset of resources, namely projective measurements on…

Quantum Physics · Physics 2025-07-24 Shishir Khandelwal , Armin Tavakoli

We address parameter estimation for complex/structured systems and suggest an effective estimation scheme based on continuous-variables quantum probes. In particular, we investigate the use of a single bosonic mode as a probe for Ohmic…

Quantum Physics · Physics 2018-01-31 Matteo Bina , Federico Grasselli , Matteo G. A. Paris

While quantum entanglement can enhance the performance of several technologies such as computing, sensing and cryptography, its widespread use is hindered by its sensitivity to noise and losses. Interestingly, even when entanglement has…

Using extensive numerical analysis of 20,000 randomly generated two-qubit states, we provide a quantitative analysis of the connection between entanglement measures and Maximized Quantum Fisher Information (MQFI). Our systematic study shows…

Quantum Physics · Physics 2025-10-03 Volkan Erol