English
Related papers

Related papers: Direct Fidelity Estimation for Generic Quantum Sta…

200 papers

Extracting information from quantum devices has long been a crucial problem in the field of quantum mechanics. By performing elaborate measurements, quantum state tomography, an important and fundamental tool in quantum science and…

Quantum Physics · Physics 2022-06-24 Yu Wang , Keren Li

We examine the physical significance of fidelity as a measure of similarity for Gaussian states, by drawing a comparison with its classical counterpart. We find that the relationship between these classical and quantum fidelities is not…

Quantum Physics · Physics 2015-06-26 H. Jeong , T. C. Ralph , W. P. Bowen

Symmetry is an important and unifying notion in many areas of physics. In quantum mechanics, it is possible to eliminate degrees of freedom from a system by leveraging symmetry to identify the possible physical transitions. This allows us…

Quantum Physics · Physics 2023-11-20 Rahul Bandyopadhyay , Alex H. Rubin , Marina Radulaski , Mark M. Wilde

We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random…

Quantum Physics · Physics 2009-11-11 Joseph Emerson , Robert Alicki , Karol Zyczkowski

Fidelity estimation is essential for the quality control of entanglement distribution networks. Because measurements collapse quantum states, we consider a setup in which nodes randomly sample a subset of the entangled qubit pairs to…

Quantum Physics · Physics 2022-10-10 Liangzhong Ruan

Measuring the distinguishability between quantum states is a basic problem in quantum information theory. In this paper, we develop optimal quantum algorithms that estimate both the trace distance and the (square root) fidelity between pure…

Quantum Physics · Physics 2024-11-27 Qisheng Wang

Quantum state tomography is a technique in quantum information science used to reconstruct the density matrix of an unknown quantum state, providing complete information about the quantum state. It is of significant importance in fields…

Quantum Physics · Physics 2025-07-23 Wenlong Zhao , Da Zhang , Huili Zhang , Haifeng Yu , Zhang-qi Yin

Adaptive tomography has been widely investigated to achieve faster state tomography processing of quantum systems. Infidelity of the nearly pure states in a quantum information process generally scales as O(1/sqrt(N) ), which requires a…

Quantum Physics · Physics 2023-05-09 Hyeok Hwang , JaeKyung Choi , Eunseong Kim

Quantum state estimation plays a crucial role in ensuring reliable creation of entanglement within quantum networks, yet conventional Quantum State Tomography (QST) methods remain resource-intensive and impractical for scaling. To address…

The fidelity susceptibility serves as a universal probe for quantum phase transitions, offering an order-parameter-free metric that captures ground-state sensitivity to Hamiltonian perturbations and exhibits critical scaling. Classical…

Quantum Physics · Physics 2025-09-03 Yukun Zhang , Xiao Yuan

Qubit-resolved operations and measurements are required for most current quantum information processing schemes. However, these operations can be experimentally costly due to the need for local addressing, demanding significant classical…

Quantum Physics · Physics 2026-05-26 Liang Mao , Yifei Wang , Yingfei Gu , Chengshu Li

We propose a quantum-state-certification protocol for stabilizer states, motivated by application in in-situ testing of NISQ-era quantum computer systems: The number of qubits is bounded, and in terms of cost of running the protocol,…

Quantum Physics · Physics 2025-07-21 Dirk Oliver Theis

Efficient verification of multipartite quantum states is crucial to many applications in quantum information processing. By virtue of Schmidt decomposition and mutually unbiased bases, here we propose a universal protocol to verify…

Quantum Physics · Physics 2026-03-04 Yunting Li , Huangjun Zhu

Experimentally quantifying entanglement and coherence are extremely important for quantum resource theory. However, because the quantum state tomography requires exponentially growing measurements with the number of qubits, it is hard to…

Quantum Physics · Physics 2020-05-13 Yue Dai , Yuli Dong , Zhenyu Xu , Wenlong You , Chengjie Zhang , Otfried Gühne

We propose and analyze a sample-efficient protocol to estimate the fidelity between an experimentally prepared state and an ideal target state, applicable to a wide class of analog quantum simulators without advanced sophisticated…

Quantum Physics · Physics 2023-09-14 Daniel K. Mark , Joonhee Choi , Adam L. Shaw , Manuel Endres , Soonwon Choi

A constant number of random Clifford measurements allows the classical shadow protocol to perform direct fidelity estimation (DFE) with high precision. However, estimating properties of an unknown quantum state is expected to be more…

Quantum Physics · Physics 2025-09-17 Hyunho Cha , Jungwoo Lee

Encoding in a high-dimensional Hilbert space improves noise resilience in quantum information processing. This approach, however, may result in cross-mode coupling and detection complexities, thereby reducing quantum cryptography…

Quantum Physics · Physics 2025-10-30 Amit Kam , Kfir Sulimany , Shai Tsesses , Uzi Pereg

The performance of a quantum information processing protocol is ultimately judged by distinguishability measures that quantify how distinguishable the actual result of the protocol is from the ideal case. The most prominent…

Quantum Physics · Physics 2023-07-13 Soorya Rethinasamy , Rochisha Agarwal , Kunal Sharma , Mark M. Wilde

Quantum state tomography (QST) is a fundamental task in quantum information science that aims to reconstruct unknown quantum states from measurement data. However, the exponential growth of Hilbert-space dimension with system size makes…

Quantum Physics · Physics 2026-05-27 Zhen Qin , Michael B. Wakin , Zhihui Zhu

A state in a d-dimensional Hilbert space can be simulated by a state defined in a different dimension with high fidelity. We assess how faithfully such the approximated state can perform quantum protocols, using an example of the squeezed…

Quantum Physics · Physics 2009-11-13 Petr Marek , M. S. Kim