English
Related papers

Related papers: Fractional revival on non-cospectral vertices

200 papers

Perfect state transfer is significant in quantum communication networks. There are very few graphs having this property. So, it is useful to find some new graphs having perfect state transfer. A good way to construct new graphs is by…

Combinatorics · Mathematics 2019-01-08 Hiranmoy Pal , Bikash Bhattacharjya

Quantum walks on undirected graphs have been studied using symmetric matrices, such as the adjacency or Laplacian matrix, and many results about perfect state transfer are known. We extend some of those results to oriented graphs. We also…

Combinatorics · Mathematics 2020-06-26 Chris Godsil , Sabrina Lato

We study perfect state transfer in Grover walks, which are typical discrete-time quantum walk models. In particular, we focus on states associated to vertices of a graph. We call such states vertex type states. Perfect state transfer…

Combinatorics · Mathematics 2021-09-15 Sho Kubota , Etsuo Segawa

We study quantum state transfer through a qubit network modeled by spins with XY interaction, when relying on a single excitation. We show that it is possible to achieve perfect transfer by shifting (adding) energy to specific vertices.…

Quantum Physics · Physics 2010-01-20 Andrea Casaccino , Seth Lloyd , Stefano Mancini , Simone Severini

The production of quantum states required for use in quantum protocols & technologies is studied by developing the tools to re-engineer a perfect state transfer spin chain so that a separable input excitation is output over multiple sites.…

Quantum Physics · Physics 2017-08-11 Alastair Kay

Perfect state transfer between two marked vertices of a graph by means of discrete-time quantum walk is analyzed. We consider the quantum walk search algorithm with two marked vertices, sender and receiver. It is shown by explicit…

Quantum Physics · Physics 2016-08-02 Martin Stefanak , Stanislav Skoupy

We develop the theory of pretty good quantum fractional revival in arbitrary sized subsets of a graph, including the theory for fractional cospectrality of subsets of arbitrary size. We use this theory to give conditions under which a…

Combinatorics · Mathematics 2023-12-01 Whitney Drazen , Mark Kempton , Gabor Lippner

This paper focuses on spectral graph convolutional neural networks (ConvNets), where filters are defined as elementwise multiplication in the frequency domain of a graph. In machine learning settings where the dataset consists of signals…

Machine Learning · Computer Science 2021-06-15 Ron Levie , Wei Huang , Lorenzo Bucci , Michael M. Bronstein , Gitta Kutyniok

A continuous-time quantum walk on a graph $X$ is represented by the complex matrix $\exp (-\mathrm{i} t A)$, where $A$ is the adjacency matrix of $X$ and $t$ is a non-negative time. If the graph models a network of interacting qubits,…

Combinatorics · Mathematics 2018-05-24 Gabriel Coutinho , Chris Godsil

A continuous-time quantum random walk describes the motion of a quantum mechanical particle on an underlying graph. The graph itself is associated with a Hilbert space of dimension equal to the number of vertices. The dynamics of the walk…

Quantum Physics · Physics 2021-09-28 Jaideep Mulherkar , Rishikant Rajdeepak , V. Sunitha

When studying the perfect transfer of a quantum state from one site to another, it is typically assumed that one can receive the arriving state at a specific instant in time, with perfect accuracy. Here, we study how sensitive perfect state…

Quantum Physics · Physics 2025-07-28 Alastair Kay , Sooyeong Kim , Christino Tamon

An example of a graph that admits balanced fractional revival between antipodes is presented. It is obtained by establishing the correspondence between the quantum walk on a hypercube where the opposite vertices across the diagonals of each…

Mathematical Physics · Physics 2018-01-17 Pierre-Antoine Bernard , Ada Chan , Érika Loranger , Christino Tamon , Luc Vinet

The unitary Cayley graph, denoted $X_n$, is the graph with vertex set ${\mathbb{Z}}_n$ such that two distinct vertices $a$ and $b$ are adjacent if $a-b=u$ for some $u$ with $1 \leq u \leq n-1$ and $\gcd(u,n) = 1$. The quadratic unitary…

Combinatorics · Mathematics 2025-08-26 Akash Kalita , Bikash Bhattacharjya

We consider quantum state transfer relative to the Laplacian matrix of a graph. Let $N(u)$ denote the set of all neighbors of a vertex $u$ in a graph $G$. A pair of vertices $u$ and $v$ are called twin vertices of $G$ provided…

Combinatorics · Mathematics 2021-09-14 Hiranmoy Pal

We consider the statistical inference problem of recovering an unknown perfect matching, hidden in a weighted random graph, by exploiting the information arising from the use of two different distributions for the weights on the edges…

Disordered Systems and Neural Networks · Physics 2020-08-10 Guilhem Semerjian , Gabriele Sicuro , Lenka Zdeborová

We study perfect state transfer in Grover walks on two important classes of graphs: strongly regular graphs and strongly walk-regular graphs. The latter class is a generalization of the former. We first give a complete classification of…

Combinatorics · Mathematics 2026-02-04 Sho Kubota , Hiroto Sekido , Harunobu Yata , Kiyoto Yoshino

A continuous-time quantum walk on a graph $G$ is given by the unitary matrix $U(t) = \exp(-itA)$, where $A$ is the Hermitian adjacency matrix of $G$. We say $G$ has pretty good state transfer between vertices $a$ and $b$ if for any…

Quantum walks, an important tool in quantum computing, have been very successfully investigated using techniques in algebraic graph theory. We are motivated by the study of state transfer in continuous-time quantum walks, which is…

Combinatorics · Mathematics 2017-10-09 Chris Godsil , Krystal Guo , Mark Kempton , Gabor Lippner

Graph states are a fundamental entanglement resource for multipartite quantum applications which are in general challenging to transform efficiently. While fusion operations for merging entangled states are well-developed, no direct…

Quantum Physics · Physics 2024-12-03 Jorge Miguel-Ramiro , Wolfgang Dür

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 matrices. As an application, we characterize fractional revival…

Combinatorics · Mathematics 2023-12-29 Hermie Monterde