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We systematise and develop a graphical approach to the investigations of quantum integrable vertex statistical models and the corresponding quantum spin chains. The graphical forms of the unitarity and various crossing relations are…

Mathematical Physics · Physics 2019-09-16 Khazret S. Nirov , Alexander V. Razumov

In this work, we present a comprehensive exploration of the entanglement and graph connectivity properties of graph states. We quantify the entanglement in pseudo graph states using the entanglement distance, a recently introduced measure…

Quantum Physics · Physics 2023-08-16 Arthur Vesperini , Roberto Franzosi

We address the question of convergence of Schr\"odinger operators on metric graphs with general self-adjoint vertex conditions as lengths of some of graph's edges shrink to zero. We determine the limiting operator and study convergence in a…

Spectral Theory · Mathematics 2019-10-23 Gregory Berkolaiko , Yuri Latushkin , Selim Sukhtaiev

We consider quantum graph states that can be mapped to directed weighted graphs, also known as directed networks. The geometric measure of entanglement of the states is calculated for the quantum graph states corresponding to arbitrary…

Quantum Physics · Physics 2024-10-01 Kh. P. Gnatenko

We give a short overview over recent developments on quantum graphs and outline the connection between general quantum graphs and so-called quantum random walks.

Quantum Physics · Physics 2015-06-26 Gregor Tanner

We discuss the meaning of geometrical constructions associated to loop quantum gravity states on a graph. In particular, we discuss the "twisted geometries" and derive a simple relation between these and Regge geometries.

General Relativity and Quantum Cosmology · Physics 2014-11-21 Carlo Rovelli , Simone Speziale

We review the theory of Cheeger constants for graphs and quantum graphs and their present and envisaged applications.

Combinatorics · Mathematics 2018-07-26 James B. Kennedy , Delio Mugnolo

This work shows that minimizing the depth of a quantum circuit composed of commuting operations reduces to a vertex coloring problem on an appropriately constructed graph, where gates correspond to vertices and edges encode…

Quantum Physics · Physics 2026-02-11 Hochang Lee , Kyung Chul Jeong , Panjin Kim

Transformers are increasingly employed for graph data, demonstrating competitive performance in diverse tasks. To incorporate graph information into these models, it is essential to enhance node and edge features with positional encodings.…

We discuss resonances for Schr\"odinger operators on metric graphs which consists of a finite compact part and a finite number of halflines attached to it; the vertex coupling is assumed to be of the $\delta$-type or certain modifications…

Mathematical Physics · Physics 2016-08-16 Pavel Exner , Jiří Lipovský

We study a set of scattering matrices of quantum graphs containing minimal number of passbands, i.e., maximal number of zero elements. The cases of even and odd vertex degree are considered. Using a solution of inverse scattering problem,…

Quantum Physics · Physics 2014-03-28 Sergey S. Poghosyan , Taksu Cheon

Quantum computing (QC) is a new computational paradigm whose foundations relate to quantum physics. Notable progress has been made, driving the birth of a series of quantum-based algorithms that take advantage of quantum computational…

Quantum Physics · Physics 2022-02-22 Yehui Tang , Junchi Yan , Hancock Edwin

We study Schr\"odinger operators on compact finite metric graphs subject to $\delta$-coupling and standard boundary conditions. We compare the $n$-th eigenvalues of those self-adjoint realizations and derive an asymptotic result for the…

Mathematical Physics · Physics 2023-09-06 Patrizio Bifulco , Joachim Kerner

Based on the main result presented in a recent paper, we derive Ambarzumian-type theorems for Schr\"odinger operators defined on quantum graphs. We recover existing results such as the classical theorem by Ambarzumian and establish some…

Spectral Theory · Mathematics 2024-05-07 Patrizio Bifulco , Joachim Kerner

In this paper we establish spectral comparison results for Schr\"odinger operators on a certain class of infinite quantum graphs, using recent results obtained in the finite setting. We also show that new features do appear on infinite…

Spectral Theory · Mathematics 2024-07-04 Patrizio Bifulco , Joachim Kerner

Using von Neumann algebras, we extend the theory of quantum computation on a graph to a theory of computation on an arbitrary topological space.

Operator Algebras · Mathematics 2024-07-23 Kazuki Ikeda

We determine the optimum topology of quasi-one dimensional nonlinear optical structures using generalized quantum graph models. Quantum graphs are relational graphs endowed with a metric and a multiparticle Hamiltonian acting on the edges,…

Quantum Physics · Physics 2015-06-19 Rick Lytel , Shoresh Shafei , Mark G. Kuzyk

We provide formulas for invariants defined on a tensor product of defining representations of unitary groups, under the action of the product group. This situation has a physical interpretation, as it is related to the quantum mechanical…

Representation Theory · Mathematics 2011-11-01 Michael W. Hero , Jeb F. Willenbring , Lauren Kelly Williams

Quantum Mechanics (QM) stands alone as a (very) successful physical theory, but the meaning of its variables and the status of many quantities in the mathematical formalism is obscure. This unique situation prompted the need for attribution…

Quantum Physics · Physics 2023-03-28 Jorge E. Horvath , Rodrigo Rosas Fernandes

A fundamental problem in quantum computation and quantum information is finding the minimum quantum dimension needed for a task. For tasks involving state preparation and measurements, this problem can be addressed using only the…

Quantum Physics · Physics 2022-07-19 Maharshi Ray , Naresh Goud Boddu , Kishor Bharti , Leong-Chuan Kwek , Adán Cabello