English
Related papers

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

200 papers

A unitary state $t$-design is an ensemble of pure quantum states whose moments match up to the $t$-th order those of states uniformly sampled from a $d$-dimensional Hilbert space. Typically, unitary state $t$-designs are obtained by…

Quantum Physics · Physics 2024-09-26 Maxwell West , Antonio Anna Mele , Martin Larocca , M. Cerezo

Decoupling has become a central concept in quantum information theory with applications including proving coding theorems, randomness extraction and the study of conditions for reaching thermal equilibrium. However, our understanding of the…

Quantum Physics · Physics 2018-02-06 Winton Brown , Omar Fawzi

One of the key ingredients of many LOCC protocols in quantum information is a multiparticle (locally) maximally entangled quantum state, aka a critical state, that possesses local symmetries. We show how to design critical states with…

Quantum Physics · Physics 2021-05-04 Oskar Słowik , Adam Sawicki , Tomasz Maciążek

We map the dynamics of entanglement in random unitary circuits, with finite on-site Hilbert space dimension $q$, to an effective classical statistical mechanics, and develop general diagrammatic tools for calculations in random unitary…

Statistical Mechanics · Physics 2019-05-29 Tianci Zhou , Adam Nahum

We study the robustness of the evolution of a quantum system against small uncontrolled variations in parameters in the Hamiltonian. We show that the fidelity susceptibility, which quantifies the perturbative error to leading order, can be…

Quantum Physics · Physics 2024-05-09 Pablo M. Poggi , Gabriele De Chiara , Steve Campbell , Anthony Kiely

We consider quantum circuit models where the gates are drawn from arbitrary gate ensembles given by probabilistic distributions over certain gate sets and circuit architectures, which we call stochastic quantum circuits. Of main interest in…

Quantum Physics · Physics 2024-11-08 Linghang Kong , Zimu Li , Zi-Wen Liu

Random quantum processes play a central role both in the study of fundamental mixing processes in quantum mechanics related to equilibration, thermalisation and fast scrambling by black holes, as well as in quantum process design and…

Quantum Physics · Physics 2017-08-29 E. Onorati , O. Buerschaper , M. Kliesch , W. Brown , A. H. Werner , J. Eisert

Assuming the polynomial hierarchy is infinite, we prove a sufficient condition for determining if uniform and polynomial size quantum circuits over a non-universal gate set are not efficiently classically simulable in the weak…

Quantum Physics · Physics 2025-10-23 Chaitanya Karamchedu , Matthew Fox , Daniel Gottesman

Randomness is an essential tool in many disciplines of modern sciences, such as cryptography, black hole physics, random matrix theory and Monte Carlo sampling. In quantum systems, random operations can be obtained via random circuits…

Quantum Physics · Physics 2017-10-24 Leonardo Banchi , Daniel Burgarth , Michael J. Kastoryano

One limitation of the variational quantum eigensolver algorithm is the large number of measurement steps required to estimate different terms in the Hamiltonian of interest. Unitary partitioning reduces this overhead by transforming the…

Quantum Physics · Physics 2021-09-01 Alexis Ralli , Peter Love , Andrew Tranter , Peter Coveney

We analyse the entanglement structure of states generated by random constant-depth two-dimensional quantum circuits, followed by projective measurements of a subset of sites. By deriving a rigorous lower bound on the average entanglement…

Quantum Physics · Physics 2025-05-21 Max McGinley , Wen Wei Ho , Daniel Malz

Unitary t-designs are some of the most versatile tools in quantum information theory. Their applications range from randomized benchmarking and shadow tomography, to more fundamental ones such as emulating quantum chaos and establishing…

Quantum Physics · Physics 2026-03-04 Namit Anand , Jeffrey Marshall , Jason Saied , Eleanor Rieffel , Andrea Morello

Random Matrix Theory is a powerful tool in applied mathematics. Three canonical models of random matrix distributions are the Gaussian Orthogonal, Unitary and Symplectic Ensembles. For matrix ensembles defined on k-fold tensor products of…

Mathematical Physics · Physics 2024-05-06 Michael Brodskiy , Owen L. Howell

We consider the problem of estimating quantum observables on a collection of qubits, given as a linear combination of Pauli operators, with shallow quantum circuits consisting of single-qubit rotations. We introduce estimators based on…

Quantum Physics · Physics 2022-08-08 Stefan Hillmich , Charles Hadfield , Rudy Raymond , Antonio Mezzacapo , Robert Wille

Given a critical quantum spin chain with a microscopic Lie-group symmetry, corresponding e.g. to $U(1)$ or $SU(2)$ spin isotropy, we numerically investigate the emergence of Kac-Moody symmetry at low energies and long distances. In that…

Strongly Correlated Electrons · Physics 2022-09-21 Ruoshui Wang , Yijian Zou , Guifre Vidal

We study the emergence of anticoncentration and approximate unitary design behavior in local Brownian circuits. The dynamics of circuit averaged moments of the probability distribution and entropies of the output state can be represented as…

Quantum Physics · Physics 2024-05-21 Subhayan Sahu , Shao-Kai Jian

We consider the classic $k$-center problem {in the constant dimensional Euclidean space} under a parallel setting, on the low-local-space Massively Parallel Computation (MPC) model, with local space per machine of ${O}(n^{\delta})$, where…

Data Structures and Algorithms · Computer Science 2026-04-21 Sam Coy , Artur Czumaj , Gopinath Mishra

We establish connections between state tomography, pseudorandomness, quantum state synthesis, and circuit lower bounds. In particular, let $\mathfrak{C}$ be a family of non-uniform quantum circuits of polynomial size and suppose that there…

Quantum Physics · Physics 2025-09-26 Nai-Hui Chia , Daniel Liang , Fang Song

We study analytically as well as numerically the dynamics of a quantum map near a quantum resonance of an order q. The map is embedded into a continuous unitary transformation generated by a time-independent quasi-Hamiltonian. Such a…

chao-dyn · Physics 2013-01-16 V. V. Sokolov , O. V. Zhirov , D. Alonso , G. Casati

Reservoir computing is a framework which is primarily used for temporal information processing, using the intrinsic dynamics of an underlying physical system. The framework, in a quantum setup, is implemented using ergodic dynamics…

Quantum Physics · Physics 2026-05-05 Gaurav Rudra Malik , Amit Kumar Jaiswal , S. Aravinda , Sunil Kumar Mishra