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Related papers: On estimating the trace of quantum state powers

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Estimating quantum entropies and divergences is an important problem in quantum physics, information theory, and machine learning. Quantum neural estimators (QNEs), which utilize a hybrid classical-quantum architecture, have recently…

Quantum Physics · Physics 2026-05-27 Sreejith Sreekumar , Ziv Goldfeld , Mark M. Wilde

Preparing the ground state of a given Hamiltonian and estimating its ground energy are important but computationally hard tasks. However, given some additional information, these problems can be solved efficiently on a quantum computer. We…

Quantum Physics · Physics 2020-12-16 Lin Lin , Yu Tong

Quantum algorithms for ground-state energy estimation of chemical systems require a high-quality initial state. However, initial state preparation is commonly either neglected entirely, or assumed to be solved by a simple product state like…

The notion of complexity of quantum states is quite different from uncertainty or information contents, and involves the tradeoff between its classical and quantum features. In this work, we we introduce a quantifier of complexity of…

Quantum Physics · Physics 2025-11-26 Siting Tang , Francesco Albarelli , Yue Zhang , Shunlong Luo , Matteo G. A. Paris

The precise quantification of the ultimate efficiency in manipulating quantum resources lies at the core of quantum information theory. However, purely information-theoretic measures fail to capture the actual computational complexity…

Quantum Physics · Physics 2025-11-19 Lorenzo Leone , Jacopo Rizzo , Jens Eisert , Sofiene Jerbi

In this work, we derive information-theoretic properties for a modified Tsallis entropy, hereinafter referred to as q-entropy. We introduce the notions of joint q-entropy, conditional q-entropy, relative q-entropy, conditional mutual…

Mathematical Physics · Physics 2026-03-31 Marco A. S. Trindade

We consider a fundamental task in quantum information theory, estimating the values of $\operatorname{tr}(O\rho)$, $\operatorname{tr}(O\rho^2)$, ..., $\operatorname{tr}(O\rho^k)$ for an observable $O$ and a quantum state $\rho$. We show…

Quantum Physics · Physics 2025-05-23 Kean Chen , Qisheng Wang , Zhan Yu , Zhicheng Zhang

I prove a basic inequality for Schatten q-norms of quantum states on a finite-dimensional bipartite Hilbert space H_1\otimes H_2: 1+||\rho||_q \ge ||\trace_1\rho||_q + ||\trace_2\rho||_q. This leads to a proof--in the finite dimensional…

Mathematical Physics · Physics 2009-11-13 Koenraad M. R. Audenaert

Non-stabilizerness, or magic, is a resource for universal quantum computation in most fault-tolerant architectures; access to states with non-stabilizerness allows for non-classically simulable quantum computation to be performed.…

Quantum Physics · Physics 2026-04-21 Benjamin Stratton

In the present study we revisit the application of the $q$-information measures $R_q$ of R\'enyi's and $S_q$ of Tsallis' to the discussion of special features of two qubits systems. More specifically, we study the correlations between the…

Quantum Physics · Physics 2015-06-26 J. Batle , M. Casas , A. Plastino , A. R. Plastino

Reconstructing the state of a complex quantum system represents a pivotal task for all quantum information applications, both for characterization purposes and for verification of quantum protocols. Recent technological developments have…

The estimation of all the parameters in an unknown quantum state or measurement device, commonly known as quantum state tomography (QST) and quantum detector tomography (QDT), is crucial for comprehensively characterizing and controlling…

Quantum Physics · Physics 2025-02-18 Shuixin Xiao , Weichao Liang , Yuanlong Wang , Daoyi Dong , Ian R. Petersen , Valery Ugrinovskii

The reconstruction of quantum states from experimental measurements, often achieved using quantum state tomography (QST), is crucial for the verification and benchmarking of quantum devices. However, performing QST for a generic…

Quantum Physics · Physics 2024-10-07 Zhen Qin , Casey Jameson , Zhexuan Gong , Michael B. Wakin , Zhihui Zhu

Joint measurements on multiple copies of a quantum state provide access to nonlinear observables such as $\operatorname{tr}(\rho^t)$, but whether replica number marks a sharp information-theoretic resource boundary has remained unclear. For…

Quantum Physics · Physics 2026-04-27 Shuai Zeng

We propose an iterative algorithm that computes the maximum-likelihood estimate in quantum state tomography. The optimization error of the algorithm converges to zero at an $O ( ( 1 / k ) \log D )$ rate, where $k$ denotes the number of…

Quantum Physics · Physics 2021-10-05 Chien-Ming Lin , Hao-Chung Cheng , Yen-Huan Li

We provide an update of the overview of imprints of Tsallis nonextensive statistics seen in a multiparticle production processes. They reveal an ubiquitous presence of power law distributions of different variables characterized by the…

High Energy Physics - Phenomenology · Physics 2015-05-30 Grzegorz Wilk , Zbigniew Wlodarczyk

Many quantum information measures can be written as an optimization of the quantum relative entropy between sets of states. For example, the relative entropy of entanglement of a state is the minimum relative entropy to the set of separable…

Quantum Physics · Physics 2018-08-09 Hamza Fawzi , Omar Fawzi

We numerically investigate entropic Bell inequalities for a pair of entangled qutrits using information-theoretic distances. We show that for this class of inequalities Tsallis entropy is more suitable than Shannon as it reveals…

Quantum Physics · Physics 2015-06-23 Marek Wajs , Pawel Kurzynski , Dagomir Kaszlikowski

We describe a protocol for cross-platform verification of quantum simulators and quantum computers. We show how to measure directly the overlap $\textrm{Tr}\left[\rho_1 \rho_2\right]$ and the purities $\textrm{Tr}\left[\rho^2_{1,2}\right]$,…

We study how heralded qubit losses during the preparation of a two-dimensional cluster state, a universal resource state for one-way quantum computation, affect its computational power. Above the percolation threshold we present a…