Five open problems in quantum information theory

P Horodecki, Ł Rudnicki, K Życzkowski - PRX Quantum, 2022 - APS
We identify five selected open problems in the theory of quantum information, which are
rather simple to formulate, are well studied in the literature, but are technically not easy. As …

Entanglement membrane in exactly solvable lattice models

MA Rampp, SA Rather, PW Claeys - Physical Review Research, 2024 - APS
Entanglement membrane theory is an effective coarse-grained description of entanglement
dynamics and operator growth in chaotic quantum many-body systems. The fundamental …

Construction and the ergodicity properties of dual unitary quantum circuits

M Borsi, B Pozsgay - Physical Review B, 2022 - APS
We consider one-dimensional quantum circuits of the brickwork type, where the fundamental
quantum gate is dual unitary. Such models are solvable: the dynamical correlation functions …

Growth of entanglement of generic states under dual-unitary dynamics

A Foligno, B Bertini - Physical Review B, 2023 - APS
Dual-unitary circuits are a class of locally interacting quantum many-body systems
displaying unitary dynamics also when the roles of space and time are exchanged. These …

Construction and local equivalence of dual-unitary operators: From dynamical maps to quantum combinatorial designs

SA Rather, S Aravinda, A Lakshminarayan - PRX Quantum, 2022 - APS
While quantum circuits built from two-particle dual-unitary (maximally entangled) operators
serve as minimal models of typically nonintegrable many-body systems, the construction …

Ternary Unitary Quantum Lattice Models and Circuits in Dimensions

RM Milbradt, L Scheller, C Aßmus, CB Mendl - Physical Review Letters, 2023 - APS
We extend the concept of dual unitary quantum gates introduced in Phys. Rev. Lett. 123,
210601 (2019) PRLTAO 0031-9007 10.1103/PhysRevLett. 123.210601 to quantum lattice …

Multi-directional unitarity and maximal entanglement in spatially symmetric quantum states

M Mestyán, B Pozsgay, IM Wanless - SciPost Physics, 2024 - scipost.org
We consider dual unitary operators and their multi-leg generalizations that have appeared at
various places in the literature. These objects can be related to multi-party quantum states …

Entanglement classification and non--separability certification via Greenberger-Horne-Zeilinger-class fidelity

M Płodzień, J Chwedeńczuk, M Lewenstein… - Physical Review A, 2024 - APS
Many-body quantum systems can be characterized using the notions of k-separability and
entanglement depth. A quantum state is k-separable if it can be expressed as a mixture of k …

Construction of perfect tensors using biunimodular vectors

SA Rather - Quantum, 2024 - quantum-journal.org
Dual unitary gates are highly non-local two-qudit unitary gates that have been studied
extensively in quantum many-body physics and quantum information in the recent past. A …

Quantum-classical correspondence in quantum channels

B Vijaywargia, A Lakshminarayan - arxiv preprint arxiv:2407.14067, 2024 - arxiv.org
Quantum channels describe subsystem or open system evolution. Using the classical
Koopman operator that evolves functions on phase space, 4 classical Koopman channels …