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Related papers: Direct dialling of Haar random unitary matrices

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Considering the problem of sampling from the output photon-counting probability distribution of a linear-optical network for input Gaussian states, we obtain results that are of interest from both quantum theory and the computational…

Quantum Physics · Physics 2015-02-16 Saleh Rahimi-Keshari , Austin P. Lund , Timothy C. Ralph

Boson Sampling is a task that is conjectured to be computationally hard for a classical computer, but which can be efficiently solved by linear-optical interferometers with Fock state inputs. Significant advances have been reported in the…

Quantum Physics · Physics 2023-04-14 Nicolò Spagnolo , Daniel J. Brod , Ernesto F. Galvão , Fabio Sciarrino

Random unitary matrices sampled from the uniform Haar ensemble have a number of important applications both in cryptography and in the simulation of a variety of fundamental physical systems. Since the Haar ensemble is very expensive to…

Quantum Physics · Physics 2022-03-25 Conrad Strydom , Mark Tame

Unitary transformations are the fundamental building blocks of gates and operations in quantum information processing allowing the complete manipulation of quantum systems in a coherent manner. In the case of photons, optical elements that…

Quantum Physics · Physics 2020-01-30 Florian Brandt , Markus Hiekkamäki , Frédéric Bouchard , Marcus Huber , Robert Fickler

Haar random states are fundamental objects in quantum information theory and quantum computing. We study the density matrix resulting from sampling $t$ copies of a $d$-dimensional quantum state according to the Haar measure on the…

Quantum Physics · Physics 2026-05-27 Tristan Nemoz , Romain Alléaume , Peter Brown

Unitary $k$-designs are distributions of unitary gates that match the Haar distribution up to its $k$-th statistical moment. They are a crucial resource for randomized quantum protocols. However, their implementation on encoded logical…

Quantum Physics · Physics 2025-08-25 Zihan Cheng , Eric Huang , Vedika Khemani , Michael J. Gullans , Matteo Ippoliti

The spectral gap of local random quantum circuits is a fundamental property that determines how close the moments of the circuit's unitaries match those of a Haar random distribution. When studying spectral gaps, it is common to bound these…

Quantum Physics · Physics 2025-12-19 Andrew E. Deneris , Pablo Bermejo , Paolo Braccia , Lukasz Cincio , M. Cerezo

This contribution describes a statistical model for decaying quantum systems (e.g. photo-dissociation or -ionization). It takes the interference between direct and indirect decay processes explicitely into account. The resulting expressions…

Chaotic Dynamics · Physics 2009-11-11 T. Gorin

Let $U_n$ be an $n \times n$ Haar unitary matrix. In this paper, the asymptotic normality and independence of $\Tr U_n, \Tr U_n^2, ..., \Tr U_n^k$ are shown by using elementary methods. More generally, it is shown that the renormalized…

Probability · Mathematics 2007-05-23 Denes Petz , Julia Reffy

Randomized measurements are useful for analyzing quantum systems especially when quantum control is not fully perfect. However, their practical realization typically requires multiple rotations in the complex space due to the adoption of…

Quantum Physics · Physics 2025-08-28 Jin-Min Liang , Satoya Imai , Shuheng Liu , Shao-Ming Fei , Otfried Gühne , Qiongyi He

The recently demonstrated possibility of entangling opposite values of the orbital angular momentum (OAM) of a photon with its spin enables the realization of nontrivial one-photon spinorbit four-dimensional states for quantum information…

We study the scaling of the convergence of several statistical properties of a recently introduced random unitary circuit ensemble towards their limits given by the circular unitary ensemble (CUE). Our study includes the full distribution…

Quantum Physics · Physics 2010-06-23 Ludovic Arnaud , Daniel Braun

Parametrized quantum optical circuits are a class of quantum circuits in which the carriers of quantum information are photons and the gates are optical transformations. Classically optimizing these circuits is challenging due to the…

Quantum Physics · Physics 2020-12-02 Filippo M. Miatto , Nicolás Quesada

The general matrix representation of a beam splitter array is presented. Each beam splitter has a transmission/reflection coefficient that determines the behavior of these individual devices and, in consequence, the whole system response.…

Quantum Physics · Physics 2024-03-18 Mario Ivan Estrada Delgado , Zurika Iveth Blanco Garcia

Boson sampling is a simple model for non-universal linear optics quantum computing using far fewer physical resources than universal schemes. An input state comprising vacuum and single photon states is fed through a Haar-random linear…

Random matrix theory is a well-developed area of probability theory that has numerous connections with other areas of mathematics and its applications. Much of the literature in this area is concerned with matrices that possess many exact…

Probability · Mathematics 2018-06-22 Ramon van Handel

Variational quantum algorithms are promising tools for near-term quantum computers as their shallow circuits are robust to experimental imperfections. Their practical applicability, however, strongly depends on how many times their circuits…

Quantum Physics · Physics 2021-09-13 Barnaby van Straaten , Bálint Koczor

The parameters of a quantum system grow exponentially with the number of involved quantum particles. Hence, the associated memory requirement goes well beyond the limit of best classic computers for quantum systems composed of a few dozen…

Quantum Physics · Physics 2021-08-31 Jakob S. Kottmann , Mario Krenn , Thi Ha Kyaw , Sumner Alperin-Lea , Alán Aspuru-Guzik

Random feature maps are ubiquitous in modern statistical machine learning, where they generalize random projections by means of powerful, yet often difficult to analyze nonlinear operators. In this paper, we leverage the "concentration"…

Machine Learning · Statistics 2021-03-18 Zhenyu Liao , Romain Couillet

Random lasers with low spatial coherence have important potential applications in high quality imaging and displaying. Here, a random laser with tunable angular spectra is proposed and fabricated through directly coupling an asymmetric…

Optics · Physics 2021-10-08 Huihui Shen , Yaoxing Bian , Junyan Li , Weinian Liu , Hanyi Xue , Zhaona Wang