English
Related papers

Related papers: Direct Fidelity Estimation for Generic Quantum Sta…

200 papers

Quantum State Tomography (QST) is a fundamental technique in Quantum Information Processing (QIP) for reconstructing unknown quantum states. However, the conventional QST methods are limited by the number of measurements required, which…

Current techniques in quantum process tomography typically return a single point estimate of an unknown process based on a finite albeit large amount of measurement data. Due to statistical fluctuations, however, other processes close to…

Quantum Physics · Physics 2019-05-15 Le Phuc Thinh , Philippe Faist , Jonas Helsen , David Elkouss , Stephanie Wehner

We describe an approach for characterizing the process of quantum gates using quantum process tomography, by first modeling them in an extended Hilbert space, which includes non-qubit degrees of freedom. To prevent unphysical processes from…

Quantum Physics · Physics 2008-11-26 Peter P. Rohde , G. J. Pryde , J. L. O'Brien , Timothy C. Ralph

Suppose, we are given two finite ensembles of pure qubit states, so that the qubits in each ensemble are prepared in identical (but unknown for us) states lying on the equator of the Bloch sphere. What is the best strategy to estimate…

Quantum Physics · Physics 2011-09-23 Michael Siomau

Quantum tomography makes it possible to obtain comprehensive information about certain logical elements of a quantum computer. In this regard, it is a promising tool for debugging quantum computers. The practical application of tomography,…

Quantum Physics · Physics 2020-12-23 B. I. Bantysh , Yu. I. Bogdanov

Neuroscientists face challenges in analyzing high-dimensional neural recording data of dense functional networks. Without ground-truth reference data, finding the best algorithm for recovering neurologically relevant networks remains an…

Quantum Physics · Physics 2025-08-28 Skylar Chan , Wilson Smith , Kyla Gabriel

Quantum entangled states of light are essential for quantum technologies and fundamental tests of physics. While quantum information science has relied on systems with entanglement in 2D degrees of freedom, e.g. quantum bits with…

Optics · Physics 2017-10-06 Matthew Reichert , Hugo Defienne , Jason W. Fleischer

Accurately characterizing multipartite entangled states is a critical challenge in quantum information processing. In this work, we focus on applying compressed sensing techniques to efficiently estimate the fidelity of…

Quantum Physics · Physics 2026-05-01 Farrokh Labib , David Nicholaeff , Vincent Russo , William J. Zeng

We apply the fidelity metric approach to analyze two recently introduced models that exhibit a quantum phase transition to a topologically ordered phase. These quantum models have a known connection to classical statistical mechanical…

Quantum Physics · Physics 2008-07-03 Damian F. Abasto , Alioscia Hamma , Paolo Zanardi

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test…

Quantum Physics · Physics 2017-10-18 H. Sosa-Martinez , N. K. Lysne , C. H. Baldwin , A. Kalev , I. H. Deutsch , P. S. Jessen

Measurement for qubits plays a key role in quantum computation. Current methods for classifying states of single qubit in a superconducting multi-qubit system produce fidelities lower than expected due to the existence of crosstalk,…

Quantum Physics · Physics 2021-09-08 Zi-Feng Chen , Qi Zhou , Peng Duan , Wei-Cheng Kong , Hai-Feng Zhang , Guo-Ping Guo

We develop a practical quantum tomography protocol and implement measurements of pure states of ququarts realized with polarization states of photon pairs (biphotons). The method is based on an optimal choice of the measuring scheme's…

Quantum Physics · Physics 2008-11-17 E. V. Moreva , Yu. I. Bogdanov , A. K. Gavrichenko , S. P. Kulik , I. Tikhonov

We propose a new approach to quantum phase transitions in terms of the density-functional fidelity, which measures the similarity between density distributions of two ground states in parameter space. The key feature of the approach, as we…

Quantum Physics · Physics 2009-11-13 Shi-Jian Gu

The development of large-scale platforms for quantum information requires new methods for verification and validation of quantum behavior. Quantum tomography (QT) is the standard tool for diagnosing quantum states, process, and readout…

Quantum Physics · Physics 2017-01-10 Charles H. Baldwin

Quantum state tomography (QST) via local measurements on reduced density matrices (LQST) is a promising approach but becomes impractical for large systems. To tackle this challenge, we developed an efficient quantum state tomography method…

Accurate and robust quantum process tomography (QPT) is crucial for verifying quantum gates and diagnosing implementation faults in experiments aimed at building universal quantum computers. However, the reliability of QPT protocols is…

The simulation of electronic properties is a pivotal issue in modern electronic structure theory, driving significant efforts over the past decades to develop protocols for computing energy derivatives. In this work, we address this problem…

We propose active steering protocols for quantum state preparation in quantum circuits where each system qubit is connected to a single detector qubit, employing a simple coupling selected from a small set of steering operators. The…

Quantum Physics · Physics 2024-03-07 Samuel Morales , Yuval Gefen , Igor Gornyi , Alex Zazunov , Reinhold Egger

In this project we examine several different quantum key distribution protocols which we divide into ones utilizing qubits whose Hilbert spaces are two dimensional and ones whose Hilbert space dimension is greater than two, these units of…

Quantum Physics · Physics 2024-02-05 Yuval Idan , Avihai Didi

The implementation and practicality of quantum algorithms highly hinge on the quality of operations within a quantum processor. Therefore, including realistic error models in quantum computing simulation platforms is crucial for testing…

Quantum Physics · Physics 2021-04-12 Ahmed Abid Moueddene , Nader Khammassi , Koen Bertels , Carmen G. Almudever
‹ Prev 1 8 9 10 Next ›