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Related papers: Optimal trace-distance bounds for free-fermionic s…

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We study correlations in a bipartite, Fermionic, free state in terms of perturbations induced by one party on the other. In particular, we show that all so conditioned free states can be modelled by an auxiliary Fermionic system and a…

Quantum Physics · Physics 2009-12-04 M. Fannes , J. Wouters

Quantum information methods have been brought to bear on high-energy physics, including the study of entanglement and Bell nonlocality in collider experiments. Quantum information observables have also been employed to constrain possible…

High Energy Physics - Phenomenology · Physics 2025-07-09 Marco Fabbrichesi , Matthew Low , Luca Marzola

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

Recent work has shown that one can efficiently learn fermionic Gaussian unitaries, also commonly known as nearest-neighbor matchcircuits or non-interacting fermionic unitaries. However, one could ask a similar question about unitaries that…

Quantum Physics · Physics 2025-06-18 Vishnu Iyer

Quantum state learning is a fundamental problem in physics and computer science. As near-term quantum devices are error-prone, it is important to design error-resistant algorithms. Apart from device errors, other unexpected factors could…

Quantum Physics · Physics 2025-08-20 Maryam Aliakbarpour , Vladimir Braverman , Nai-Hui Chia , Yuhan Liu

The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the…

Here we present an efficient and numerically stable procedure for compressing a correlation matrix into a set of local unitary single-particle gates, which leads to a very efficient way of forming the matrix product state (MPS)…

Strongly Correlated Electrons · Physics 2015-08-26 Matthew T. Fishman , Steven R. White

We study quantum state testing where the goal is to test whether $\rho=\rho_0\in\mathbb{C}^{d\times d}$ or $\|\rho-\rho_0\|_1>\varepsilon$, given $n$ copies of $\rho$ and a known state description $\rho_0$. In practice, not all measurements…

Quantum Physics · Physics 2024-09-02 Yuhan Liu , Jayadev Acharya

We provide a bound for the trace distance between two quantum states. The lower bound is based on the superfidelity, which provides the upper bound on quantum fidelity. One of the advantages of the presented bound is that it can be…

Quantum Physics · Physics 2009-02-11 Zbigniew Puchała , Jarosław Adam Miszczak

The optimal quantum measurements for estimating different unknown parameters in a parameterized quantum state are usually incompatible with each other. Traditional approaches to addressing the measurement incompatibility issue, such as the…

Quantum Physics · Physics 2026-02-03 Sisi Zhou , Senrui Chen

Recently, the much-used trace distance of coherence was shown to not be a proper measure of coherence, so a modification of it was proposed. We derive an explicit formula for this modified trace distance of coherence on pure states. Our…

Quantum Physics · Physics 2019-05-30 Nathaniel Johnston , Chi-Kwong Li , Sarah Plosker

We consider the problem of local operations and classical communication (LOCC) discrimination between two bipartite pure states of fermionic systems. We show that, contrary to the case of quantum systems, for fermionic systems it is…

Quantum Physics · Physics 2020-09-14 Matteo Lugli , Paolo Perinotti , Alessandro Tosini

Open effective field theories provide a systematic framework for describing physical systems interacting with an environment whose microscopic details are unknown, unobservable, or uncalculable. A basic step in constructing any effective…

High Energy Physics - Theory · Physics 2026-05-25 Enrica Lausdei , Enrico Pajer

Topological phases are generally characterized by topological invariants denoted by integer numbers. However, different topological systems often require different topological invariants to measure, such as geometric phases, topological…

Mesoscale and Nanoscale Physics · Physics 2024-05-07 ZhaoXiang Fang , Ming Gong , Guang-Can Guo , Yongxu Fu , Long Xiong

Quantum state tomography, which aims to find the best description of a quantum state -- the density matrix, is an essential building block in quantum computation and communication. Standard techniques for state tomography are incapable of…

Quantum Physics · Physics 2022-11-18 Markus Rambach , Akram Youssry , Marco Tomamichel , Jacquiline Romero

The fidelity estimation between two quantum states is crucial for quantum computation and information science. However, an efficacious method for this, especially for mixed states and higher-dimensional density matrices, remains elusive.…

Quantum Physics · Physics 2026-05-11 Anumita Mukhopadhyay , Shibdas Roy , Arun Kumar Pati

The initialization of a quantum system into a certain state is a crucial aspect of quantum information science. While a variety of measurement strategies have been developed to characterize how well the system is initialized, for a given…

The quantum efficiency in the transfer of an initial excitation in disordered finite networks, modeled by the $k$-body embedded Gaussian ensembles of random matrices, is studied for bosons and fermions. The influence of the presence or…

Quantum Physics · Physics 2015-11-12 Adrian Ortega , Manan Vyas , Luis Benet

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

One of the most important questions in quantum information theory is the so-called separability problem. It involves characterizing the set of separable (or, equivalently entangled) states among mixed states of a multipartite quantum…

Quantum Physics · Physics 2014-12-16 Michał Oszmaniec