activity
20112026
most citedQuantifying the coherence of pure quantum states

34 citations · 207 across the 35 of their papers we have counts for

collaborators

41 papers

math.CO2026

Enumeration of Laplacian integral and {-1,0,1}-diagonalizable graphs

Nathaniel Johnston, Sarah Plosker, Luis M. B. Varona

A graph with Laplacian matrix is called Laplacian integral if the eigenvalues of are all integers, and it is called -diagonalizable if has a full set of eig…

quant-ph2026

Graph Structures for Local Distinguishability of Quantum Product States

Sooyeong Kim, David W. Kribs, Michael Nathanson +2

We consider the problem of distinguishing sets of quantum product states with local operations and classical communication (LOCC). Recent work has used graph theory to identify set…

math.FA2025

Generalizing the Cauchy-Schwarz inequality: Hadamard powers and tensor products

Nathaniel Johnston, Sarah Plosker, Charles Torrance +1

We explore and generalize a Cauchy-Schwarz-type inequality originally proved in [Electronic Journal of Linear Algebra 35, 156-180 (2019)]: $\|\mathbf{v}^2\|\|\mathbf{w}^2\| - \lang…

math.CO2024★ 2 cited

The Factor Width Rank of a Matrix

Nathaniel Johnston, Shirin Moein, Sarah Plosker

A matrix is said to have factor width at most if it can be written as a sum of positive semidefinite matrices that are non-zero only in a single principal submatri…

math.CO2023★ 2 cited

Laplacian - and -diagonalizable graphs

Nathaniel Johnston, Sarah Plosker

A graph is called "Laplacian integral" if the eigenvalues of its Laplacian matrix are all integers. We investigate the subset of these graphs whose Laplacian is furthermore diagona…

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…

quant-ph2022★ 6 cited

Absolutely -Incoherent Quantum States and Spectral Inequalities for Factor Width of a Matrix

Nathaniel Johnston, Shirin Moein, Rajesh Pereira +1

We investigate the set of quantum states that can be shown to be -incoherent based only on their eigenvalues (equivalently, we explore which Hermitian matrices can be shown to h…

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…

quant-ph2021★ 3 cited

Birkhoff-James Orthogonality in the Trace Norm, with Applications to Quantum Resource Theories

Nathaniel Johnston, Shirin Moein, Rajesh Pereira +1

We develop numerous results that characterize when a complex Hermitian matrix is Birkhoff-James orthogonal, in the trace norm, to a (Hermitian) positive semidefinite matrix or set…

cs.CY2021

Expanding Cybersecurity Knowledge Through an Indigenous Lens: A First Look

Farrah Huntinghawk, Candace Richard, Sarah Plosker +1

Decolonization and Indigenous education are at the forefront of Canadian content currently in Academia. Over the last few decades, we have seen some major changes in the way in whi…

math.OA2021

Universality of Weyl Unitaries

Douglas Farenick, Oluwatobi Ruth Ojo, Sarah Plosker

Weyl's unitary matrices, which were introduced in Weyl's 1927 paper on group theory and quantum mechanics, are unitary matrices given by the diagonal matrix whose entri…

math.CO2020

The Complete Positivity of Symmetric Tridiagonal and Pentadiagonal Matrices

Lei Cao, Darian McLaren, Sarah Plosker

We provide a decomposition that is sufficient in showing when a symmetric tridiagonal matrix is completely positive. Our decomposition can be applied to a wide range of matrice…

math.OA2020

Complete Order Equivalence of Spin Unitaries

Douglas Farenick, Farrah Huntinghawk, Adili Masanika +1

This paper is a study of linear spaces of matrices and linear maps on matrix algebras that arise from \emph{spin systems}, or \emph{spin unitaries}, which are finite sets $\mathcal…

math.FA2020★ 1 cited

Bistochastic operators and quantum random variables

Sarah Plosker, Christopher Ramsey

Given a positive operator-valued measure acting on the Borel sets of a locally compact Hausdorff space , with outcomes in the algebra of all bounded…

math.CO2020★ 1 cited

Complex Hadamard Diagonalisable Graphs

Ada Chan, Shaun Fallat, Steve Kirkland +3

In light of recent interest in Hadamard diagonalisable graphs (graphs whose Laplacian matrix is diagonalisable by a Hadamard matrix), we generalise this notion from real to complex…

math.CO2019

Centrosymmetric Stochastic Matrices

Lei Cao, Darian McLaren, Sarah Plosker

We consider the convex set of stochastic matrices and the convex set of centrosymmetric stochastic matrices (stochastic…

math.OA2019★ 4 cited

Quantum Majorization on Semifinite von Neumann Algebras

Priyanga Ganesan, Li Gao, Satish K. Pandey +1

We extend Gour et al's characterization of quantum majorization via conditional min-entropy to the context of semifinite von Neumann algebras. Our method relies on a connection bet…

math.SP2019★ 1 cited

Achievable multiplicity partitions in the inverse eigenvalue problem of a graph

Mohammad Adm, Shaun Fallat, Karen Meagher +3

Associated to a graph is a set of all real-valued symmetric matrices whose off-diagonal entries are nonzero precisely when the corresponding vertices of the gr…

quant-ph2018★ 3 cited

Approximately Clean Quantum Probability Measures

Douglas Farenick, Remus Floricel, Sarah Plosker

A quantum probability measure--or quantum measurement--is said to be clean if it cannot be irreversibly connected to any other quantum probability measure via a quantum channel. Th…

quant-ph2018★ 7 cited

Schur multipliers and mixed unitary maps

Samuel J. Harris, Rupert H. Levene, Vern I. Paulsen +2

We consider the tensor product of the completely depolarising channel on matrices with the map of Schur multiplication by a correlation matrix and characte…

math.FA2018

A simplified and unified generalization of some majorization results

Shirin Moein, Rajesh Pereira, Sarah Plosker

We consider positive, integral-preserving linear operators acting on space, known as stochastic operators or Markov operators. We show that, on finite-dimensional spaces, any…

quant-ph2018★ 19 cited

Some notes on the robustness of k-coherence and k-entanglement

Nathaniel Johnston, Chi-Kwong Li, Sarah Plosker +2

We show that two related measures of k-coherence, called the standard and generalized robustness of k-coherence, are equal to each other when restricted to pure states. As a direct…

math.CO2018

Switching and partially switching the hypercube while maintaining perfect state transfer

Steve Kirkland, Sarah Plosker, Xiaohong Zhang

A graph is said to exhibit perfect state transfer (PST) if one of its corresponding Hamiltonian matrices, which are based on the vertex-edge structure of the graph, gives rise to P…

math.FA2018

An operator-valued Lyapunov theorem

Sarah Plosker, Christopher Ramsey

We generalize Lyapunov's convexity theorem for classical (scalar-valued) measures to quantum (operator-valued) measures. In particular, we show that the range of a nonatomic quantu…