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20212026
most citedStrong Cospectrality and Twin Vertices in Weighted Graphs

10 citations · 32 across the 19 of their papers we have counts for

collaborators

21 papers

math.CO2026

Quantum walks and graph operations

Joy Cooper, Homer De Vera, Hermie Monterde +3

Let be the transition matrix of a quantum walk on a graph relative to its adjacency matrix or the Laplacian matrix . This paper investigates the behavior of qua…

math.CO2026

Near-factorizations in association schemes

Allen Herman, Alice Lacaze-Masmonteil, Karen Meagher +1

We formally initiate the study of -fold near-factorizations in association schemes. Namely, given an association , we consider the existence of a facto…

quant-ph2026

Perfect -state transfer

Stephen Kirkland, Hermie Monterde, Sarah Plosker

Much work has been done in the last two decades on the topic of quantum state transfer in a quantum spin network. One can model such a system of interacting qubits using an undirec…

math.CO2026

Maximum spectral sum of graphs

Hitesh Kumar, Lele Liu, Hermie Monterde +2

For a graph of order , the spectral sum of is defined to be the sum , where (resp. ) is the largest (resp. second largest) adjacency ei…

math.CO2026

Laplacian state transfer in graphs with involutions

Swornalata Ojha, Hermie Monterde, Hiranmoy Pal

For , the generalized Laplacian of a graph is the matrix , where is the degree matrix and is the adjacency matrix of $X…

math.CO2026

Local -uniform mixing in continuous quantum walks

Hermie Monterde

Let be a weighted graph and be its adjacency, Laplacian or signless Laplacian matrix. In a continuous quantum walk on , local -uniform mixing occurs at vertex if…

math.CO2026

Sedentary quantum walks on bipartite and planar graphs

Karen Meagher, Hermie Monterde

If a quantum walk starting on a vertex tends to stay at home, then that vertex is said to be sedentary. We prove that almost all planar graphs and almost all trees contain at least…

math.CO2026

Structured eigenbases and pair state transfer on threshold graphs

Leonardo de Lima, Renata Del-Vecchio, Hermie Monterde +1

Recently, Macharete, Del-Vecchio, Teixeira and de Lima showed that a star and any threshold graph on the same number of vertices share the same eigenbasis relative to the Laplacian…

math.CO2025

Quantum walks on finite and bounded infinite graphs

Chris Godsil, Steve Kirkland, Sarojini Mohapatra +2

A weighted graph with countable vertex set is bounded if there is an upper bound on the maximum of the sum of absolute values of all edge weights incident to a vertex in . I…

math.CO2025

More graphs with pair state transfer

Hermie Monterde, Hiranmoy Pal

This paper has two main goals. First, we characterize perfect state transfer between -pair states in strongly regular graphs, as well as graphs in association schemes admitting…

math.CO2025

Laplacian quantum walks on blow-up graphs

Hermie Monterde, Hiranmoy Pal, Steve Kirkland

This paper is a sequel to the work of Bhattacharjya et al.\ (J. Phys. A-Math. 57.33: 335303, https://doi.org/10.1088/1751-8121/ad6653) on quantum state transfer on blow-up graphs,…

quant-ph2025

Perfect state transfer between real pure states

Chris Godsil, Stephen Kirkland, Hermie Monterde

Pure states correspond to one-dimensional subspaces of represented by unit vectors. In this paper, we develop the theory of perfect state transfer (PST) between real…

quant-ph2024

A generalization of quantum pair state transfer

Sooyeong Kim, Hermie Monterde, Bahman Ahmadi +3

An -pair state in a graph is a quantum state of the form , where and are vertices in the graph and is a non-zero complex number. If $s=-1…

math.CO2023

New results in vertex sedentariness

Hermie Monterde

A vertex in a graph is said to be sedentary if a quantum state assigned on that vertex tends to stay on that vertex. Under mild conditions, we show that the direct product and join…

quant-ph2023★ 1 cited

Quantum walks on join graphs

Steve Kirkland, Hermie Monterde

The join of two graphs and is the graph obtained by joining each vertex of to each vertex of . We explore the behaviour of a continuous quantum walk on a w…

quant-ph2023

Quantum walks on blow-up graphs

Bikash Bhattacharjya, Hermie Monterde, Hiranmoy Pal

A blow-up of copies of a graph is the graph obtained by replacing every vertex of by an independent set of size , where the copies of vertices…

math.CO2023

Weakly Hadamard diagonalizable graphs and Quantum State Transfer

Darian McLaren, Hermie Monterde, Sarah Plosker

Hadamard diagonalizable graphs are undirected graphs for which the corresponding Laplacian is diagonalizable by a Hadamard matrix. Such graphs have been studied in the context of q…

math.CO2023★ 6 cited

Fractional revival between twin vertices

Hermie Monterde

In this paper, we provide a characterization of fractional revival between twin vertices in a weighted graph with respect to its adjacency, Laplacian and signless Laplacian matrice…

quant-ph2023★ 6 cited

Sedentariness in quantum walks

Hermie Monterde

We formalize the notion of a sedentary vertex and present a relaxation of the concept of a sedentary family of graphs introduced by Godsil [Linear Algebra Appl. 614:356-375, 2021].…

math.CO2022★ 9 cited

Quantum state transfer between twins in weighted graphs

Stephen Kirkland, Hermie Monterde, Sarah Plosker

Twin vertices in simple unweighted graphs are vertices that have the same neighbours and, in the case of weighted graphs with possible loops, the corresponding incident edges have…

math.CO2021★ 10 cited

Strong Cospectrality and Twin Vertices in Weighted Graphs

Hermie Monterde

We explore algebraic and spectral properties of weighted graphs containing twin vertices that are useful in quantum state transfer. We extend the notion of adjacency strong cospect…