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Related papers: Unitary k-designs from random number-conserving qu…

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Unitary $2$-designs are random unitaries simulating up to the second order statistical moments of the uniformly distributed random unitaries, often referred to as Haar random unitaries. They are used in a wide variety of theoretical and…

Quantum Physics · Physics 2017-06-01 Yoshifumi Nakata , Christoph Hirche , Ciara Morgan , Andreas Winter

We study the formation of short-depth designs beyond the unitary group. We provide a range of results on several groups of broad interest in quantum information science: the Clifford group, the orthogonal group, the unitary symplectic…

Unitary designs are unitary ensembles that emulate Haar-random unitary statistics. They provide a vital tool for studying quantum randomness and have found broad applications in quantum technologies. However, existing research has focused…

Quantum Physics · Physics 2026-01-06 Xiaodong Yang , Jiaqing Leng , Jun Li

We prove that local random quantum circuits acting on n qubits composed of O(t^{10} n^2) many nearest neighbor two-qubit gates form an approximate unitary t-design. Previously it was unknown whether random quantum circuits were a t-design…

Quantum Physics · Physics 2019-07-11 Fernando G. S. L. Brandao , Aram W. Harrow , Michal Horodecki

Given a universal gate set on two qubits, it is well known that applying random gates from the set to random pairs of qubits will eventually yield an approximately Haar-distributed unitary. However, this requires exponential time. We show…

Quantum Physics · Physics 2015-05-13 Aram W. Harrow , Richard A. Low

Unitary $T$-designs play an important role in quantum information, with diverse applications in quantum algorithms, benchmarking, tomography, and communication. Until now, the most efficient construction of unitary $T$-designs for $n$-qudit…

Quantum Physics · Physics 2025-02-18 Chi-Fang Chen , Jordan Docter , Michelle Xu , Adam Bouland , Patrick Hayden

The nature of randomness and complexity growth in systems governed by unitary dynamics is a fundamental question in quantum many-body physics. This problem has motivated the study of models such as local random circuits and their…

Quantum Physics · Physics 2025-10-10 Laura Cui , Thomas Schuster , Liang Mao , Hsin-Yuan Huang , Fernando Brandao

Constructing ensembles of circuits which efficiently approximate the Haar measure over various groups is a long-standing and fundamental problem in quantum information theory. Recently it was shown that one can obtain approximate designs…

Quantum Physics · Physics 2025-06-23 Maxwell West , Diego García-Martín , N. L. Diaz , M. Cerezo , Martin Larocca

Recent years have enjoyed a strong interest in exploring properties and applications of random quantum circuits. In this work, we explore the ensemble of $t$-doped Clifford circuits on $n$ qubits, consisting of Clifford circuits…

Quantum Physics · Physics 2026-05-06 Lorenzo Leone , Salvatore F. E. Oliviero , Alioscia Hamma , Jens Eisert , Lennart Bittel

In this work, we study distributions of unitaries generated by random quantum circuits containing only symmetry-respecting gates. We develop a unified approach applicable to all symmetry groups and obtain an equation that determines the…

Quantum Physics · Physics 2024-10-16 Hanqing Liu , Austin Hulse , Iman Marvian

Efficient methods for generating pseudo-randomly distributed unitary operators are needed for the practical application of Haar distributed random operators in quantum communication and noise estimation protocols. We develop a theoretical…

Quantum Physics · Physics 2009-11-11 Joseph Emerson , Etera Livine , Seth Lloyd

We provide new constructions of unitary $t$-designs for general $t$ on one qudit and $N$ qubits, and propose a design Hamiltonian, a random Hamiltonian of which dynamics always forms a unitary design after a threshold time, as a basic…

Quantum Physics · Physics 2017-04-25 Yoshifumi Nakata , Christoph Hirche , Masato Koashi , Andreas Winter

Quantum error correction and symmetries play central roles in quantum information science and physics. It is known that quantum error-correcting codes covariant with respect to continuous symmetries cannot correct erasure errors perfectly…

Quantum Physics · Physics 2021-02-24 Linghang Kong , Zi-Wen Liu

The realization of unitary designs is of fundamental interest in quantum science and typically requires the ability to implement structured quantum circuits. Recent developments have explored the possibility of generating unitary designs…

Quantum Physics · Physics 2026-04-14 Ning Sun , Pengfei Zhang

We study the scrambling of quantum information in local random unitary circuits by focusing on the tripartite information proposed by Hosur et al. We provide exact results for the averaged R\'enyi-$2$ tripartite information in two cases:…

Statistical Mechanics · Physics 2020-08-18 Bruno Bertini , Lorenzo Piroli

We study the relationship between quantum chaos and pseudorandomness by developing probes of unitary design. A natural probe of randomness is the "frame potential," which is minimized by unitary $k$-designs and measures the $2$-norm…

Quantum Physics · Physics 2017-05-24 Daniel A. Roberts , Beni Yoshida

We prove that $poly(t) \cdot n^{1/D}$-depth local random quantum circuits with two qudit nearest-neighbor gates on a $D$-dimensional lattice with n qudits are approximate $t$-designs in various measures. These include the "monomial"…

Quantum Physics · Physics 2023-05-05 Aram Harrow , Saeed Mehraban

Random many-body states are both a useful tool to model certain physical systems and an important asset for quantum computation. Realising them, however, generally requires an exponential (in system size) amount of resources. Recent…

Quantum Physics · Physics 2025-03-10 Jonathon Riddell , Katja Klobas , Bruno Bertini

We investigate circuit complexity of unitaries generated by time evolution of randomly chosen strongly interacting Hamiltonians in finite dimensional Hilbert spaces. Specifically, we focus on two ensembles of random generators -- the so…

Quantum Physics · Physics 2025-03-04 Marcin Kotowski , Michał Oszmaniec , Michał Horodecki

Unitary $k$-designs are finite ensembles of unitary matrices that approximate the Haar distribution over unitary matrices. Several ensembles are known to be 2-designs, including the uniform distribution over the Clifford group, but no…

Quantum Physics · Physics 2016-11-10 Zak Webb