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Related papers: Quantum graphs where back-scattering is prohibited

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Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other…

Quantum Physics · Physics 2023-04-04 Anne Broadbent , Christian Schaffner

We present a few combinatorial identities which were encountered in our work on the spectral theory of quantum graphs. They establish a new connection between the theory of random matrix ensembles and combinatorics.

Mathematical Physics · Physics 2007-05-23 Holger Schanz , Uzy Smilansky

Vertex coloring and multicoloring of graphs are a well known subject in graph theory, as well as their applications. In vertex multicoloring, each vertex is assigned some subset of a given set of colors. Here we propose a new kind of vertex…

Combinatorics · Mathematics 2018-09-13 Tanja Vojković , Damir Vukičević , Vinko Zlatić

Finding hidden layers in complex networks is an important and a non-trivial problem in modern science. We explore the framework of quantum graphs to determine whether concealed parts of a multi-layer system exist and if so then what is…

Disordered Systems and Neural Networks · Physics 2021-10-04 Łukasz G. Gajewski , Julian Sienkiewicz , Janusz A. Hołyst

A continuous-time quantum walk is modelled using a graph. In this short paper, we provide lower bounds on the size of a graph that would allow for some quantum phenomena to occur. Among other things, we show that, in the adjacency matrix…

Combinatorics · Mathematics 2018-05-23 Gabriel Coutinho

We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite…

Quantum Physics · Physics 2012-02-02 Benjamin A. Blumer , Michael S. Underwood , David L. Feder

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 generalize the concept of token graphs to obtain supertoken graphs. In the latter case, there can be more than one token in a vertex. We formally define supertoken graphs and establish their basic properties. Moreover, we provide some…

Combinatorics · Mathematics 2026-04-08 Mónica A. Reyes , Cristina Dalfó , Miquel Àngel Fiol

Graphene quantum dots provide a platform for manipulating electron behaviors in two-dimensional (2D) Dirac materials. Most previous works were of the "forward" type in that the objective was to solve various confinement, transport and…

Mesoscale and Nanoscale Physics · Physics 2022-12-28 Chen-Di Han , Ying-Cheng Lai

Society relies and depends increasingly on information exchange and communication. In the quantum world, security and privacy is a built-in feature for information processing. The essential ingredient for exploiting these quantum advantages…

Quantum Physics · Physics 2016-05-27 Michael Epping , Hermann Kampermann , Dagmar Bruß

We develop a geometric scattering theory for a geometrically finite group acting on (a vector bundle over) a symmetric space of negative curvature. In particular, we obtain the meromorphic continuation of Eisenstein series and scattering…

Differential Geometry · Mathematics 2007-11-28 Ulrich Bunke , Martin Olbrich

We define a new class of integrable vertex models associated to quantum groups at roots of unit

High Energy Physics - Theory · Physics 2015-06-26 A. Berkovich , C. Gomez , G. SIERRA

Whenever graphs admit equitable partitions, their quotient graphs highlight the structure evidenced by the partition. It is therefore very natural to ask what can be said about two graphs that have the same quotient according to certain…

Combinatorics · Mathematics 2024-11-15 Frederico Cançado , Gabriel Coutinho

Spin networks, essentially labeled graphs, are ``good quantum numbers'' for the quantum theory of geometry. These structures encompass a diverse range of techniques which may be used in the quantum mechanics of finite dimensional systems,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Seth A. Major

Quantum graphs have been introduced by Duan, Severini, and Winter to describe the zero-error behaviour of quantum channels. Since then, quantum graph theory has become a field of study in its own right. A substantial source of difficulty in…

Operator Algebras · Mathematics 2026-04-20 Gian Luca Spitzer , Ion Nechita

We derive a formula for the level spacing probability distribution in quantum graphs. We apply it to simple examples and we discuss its relation with previous work and its possible application in more general cases. Moreover, we derive an…

Quantum Physics · Physics 2015-06-26 F. Barra , P. Gaspard

In what follows we first set the context for inverse scattering in nuclear physics with a brief account of inverse problems in general. We then turn to inverse scattering which involves the S-matrix, which connects the interaction potential…

Nuclear Theory · Physics 2012-05-03 Raymond S. Mackintosh

We establish an upper bound on the spectral gap for compact quantum graphs which depends only on the diameter and total number of vertices. This bound is asymptotically sharp for pumpkin chains with number of edges tending to infinity.

Spectral Theory · Mathematics 2019-05-09 David Borthwick , Livia Corsi , Kenny Jones

We consider the scattering matrix approach to quantum electron transport in meso- and nano-conductors. This approach is an alternative to the more conventional kinetic equation and Green's function approaches, and often is more efficient…

Mesoscale and Nanoscale Physics · Physics 2015-04-09 G. B. Lesovik , I. A. Sadovskyy

Given a unitary operator in a finite dimensional complex Hilbert space, its unitary reduction to a subspace is defined. The application to quantum graphs is discussed. It is shown how the reduction allows to generate the scattering matrices…

Quantum Physics · Physics 2025-01-10 L. L. Salcedo