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Related papers: Efficient quantum tomography II

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Efficient sampling from a classical Gibbs distribution is an important computational problem with applications ranging from statistical physics over Monte Carlo and optimization algorithms to machine learning. We introduce a family of…

Quantum Physics · Physics 2021-09-08 Dominik S. Wild , Dries Sels , Hannes Pichler , Cristian Zanoci , Mikhail D. Lukin

Modern day quantum simulators can prepare a wide variety of quantum states but the accurate estimation of observables from tomographic measurement data often poses a challenge. We tackle this problem by developing a quantum state tomography…

Quantum Physics · Physics 2022-09-27 Tobias Schmale , Moritz Reh , Martin Gärttner

The impressive pace of advance of quantum technology calls for robust and scalable techniques for the characterization and validation of quantum hardware. Quantum process tomography, the reconstruction of an unknown quantum channel from…

Quantum state tomography is a powerful, but resource-intensive, general solution for numerous quantum information processing tasks. This motivates the design of robust tomography procedures that use relevant resources as sparingly as…

Quantum Physics · Physics 2022-01-17 Fernando G. S. L. Brandão , Richard Kueng , Daniel Stilck França

We revisit quantum tomography in an informationally incomplete scenario and propose improved state reconstruction methods using deep neural networks. In the first approach, the trained network predicts an optimal linear or quadratic…

Quantum Physics · Physics 2026-01-21 Mateusz Krawczyk , Pavel Baláž , Katarzyna Roszak , Jarosław Pawłowski

Quantum State Tomography is the task of determining an unknown quantum state by making measurements on identical copies of the state. Current algorithms are costly both on the experimental front -- requiring vast numbers of measurements --…

Quantum Physics · Physics 2018-12-18 Yihui Quek , Stanislav Fort , Hui Khoon Ng

Scalable quantum technologies will present challenges for characterizing and tuning quantum devices. This is a time-consuming activity, and as the size of quantum systems increases, this task will become intractable without the aid of…

With the rise of quantum technologies, data security increasingly relies on quantum cryptography and its most notable application, quantum key distribution (QKD). Yet, current technological limitations, in particular, the unavailability of…

Quantum tomography is a process of quantum state reconstruction using data from multiple measurements. An essential goal for a quantum tomography algorithm is to find measurements that will maximize the useful information about an unknown…

Quantum Physics · Physics 2020-08-05 A. D. Moiseevskiy , G. I. Struchalin , S. S. Straupe , S. P. Kulik

It has previously been shown that quantum state tomography can be used to increase the key rate of quantum key distribution (QKD) for the special case of qubits (i.e.,d=2). Here, we consider the case of higher dimensions, i.e., qudits, and…

Quantum Physics · Physics 2020-08-27 Yongtao Zhan , Hoi-Kwong Lo

We develop techniques to analyse the statistics of completion times of non-deterministic elements in quantum entanglement generation, and how they affect the overall performance as measured by the secret key rate. By considering such…

Quantum Physics · Physics 2019-04-10 Scott E. Vinay , Pieter Kok

We use a meta-learning neural-network approach to analyse data from a measured quantum state. Once our neural network has been trained it can be used to efficiently sample measurements of the state in measurement bases not contained in the…

Quantum Physics · Physics 2021-07-01 Alistair W. R. Smith , Johnnie Gray , M. S. Kim

We study asymptotics of random shifted Young diagrams which correspond to a given sequence of reducible projective representations of the symmetric groups. We show limit results (Law of Large Numbers and Central Limit Theorem) for their…

Combinatorics · Mathematics 2020-02-06 Sho Matsumoto , Piotr Śniady

We study long $r$-twins in random words and permutations. Motivated by questions posed in works of Dudek-Grytczuk-Ruci\'nski, we obtain the following. For a uniform word in $[k]^n$ we prove sharp one-sided tail bounds showing that the…

Combinatorics · Mathematics 2025-10-07 Elliott Liu , Linus Tang , Jessica Wan

We introduce an optimal strategy to sample quantum outcomes of local measurement strings for isometric tensor network states. Our method generates samples based on an exact cumulative bounding function, without prior knowledge, in the…

Quantum Physics · Physics 2025-04-23 Marco Ballarin , Pietro Silvi , Simone Montangero , Daniel Jaschke

We investigate optimal encoding and retrieval of digital data, when the storage/communication medium is described by quantum mechanics. We assume an m-ary alphabet with arbitrary prior distribution, and an n-dimensional quantum system.…

Quantum Physics · Physics 2007-05-23 Noam Elron , Yonina C. Eldar

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 propose a new method to extend the size of a quantum computation beyond the number of physical qubits available on a single device. This is accomplished by randomly inserting measure-and-prepare channels to express the output state of a…

We study different techniques that allow us to gain complete knowledge about an unknown quantum state, e.g. to perform full tomography of this state. We focus on two apparently simple cases, full tomography of one and two qubit systems. We…

Quantum Physics · Physics 2007-05-23 Thomas Durt

As quantum technologies advance, the ability to generate increasingly large quantum states has experienced rapid development. In this context, the verification and estimation of large entangled systems represents one of the main challenges…

Quantum Physics · Physics 2022-03-30 Joshua Morris , Valeria Saggio , Aleksandra Gočanin , Borivoje Dakić