English
Related papers

Related papers: Laplacian pair state transfer in Q-graph

200 papers

The study of perfect state transfer on graphs has attracted a great deal of attention during the past ten years because of its applications to quantum information processing and quantum computation. Perfect state transfer is understood to…

Combinatorics · Mathematics 2023-05-30 Shixin Wang , Tao Feng

Quantum state transfer within a quantum computer can be achieved by using a network of qubits, and such a network can be modelled mathematically by a graph. Here, we focus on the corresponding Laplacian matrix, and those graphs for which…

Quantum Physics · Physics 2022-11-28 Nathaniel Johnston , Steve Kirkland , Sarah Plosker , Rebecca Storey , Xiaohong Zhang

We consider a system of qubits coupled via nearest-neighbour interaction governed by the Heisenberg Hamiltonian. We further suppose that all coupling constants are equal to $1$. We are interested in determining which graphs allow for a…

Combinatorics · Mathematics 2018-05-23 Gabriel Coutinho , Henry Liu

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 equal weights. In this paper, we explore the role of twin…

Combinatorics · Mathematics 2023-12-29 Stephen Kirkland , Hermie Monterde , Sarah Plosker

We prove new results on perfect state transfer of quantum walks on quotient graphs. Since a graph $G$ has perfect state transfer if and only if its quotient $G/\pi$, under any equitable partition $\pi$, has perfect state transfer, we…

Quantum Physics · Physics 2012-11-05 R. Bachman , E. Fredette , J. Fuller , M. Landry , M. Opperman , C. Tamon , A. Tollefson

We study perfect state transfer of quantum walks on signed graphs. Our aim is to show that negative edges are useful for perfect state transfer. Specific results we prove include: (1) The signed join of a negative 2-clique with any positive…

Quantum Physics · Physics 2013-01-17 J. Brown , C. Godsil , D. Mallory , A. Raz , C. Tamon

In this paper, we investigate the existence of Laplacian perfect state transfer and Laplacian pretty good state transfer in vertex complemented coronas. We prove that there is no Laplacian perfect state transfer in vertex complemented…

Quantum Physics · Physics 2022-02-16 Qiang Wang , Xiaogang Liu

The question of perfect state transfer existence in quantum spin networks based on weighted graphs has been recently presented by many authors. We give a simple condition for characterizing weighted circulant graphs allowing perfect state…

Discrete Mathematics · Computer Science 2011-04-12 Milan Bašić

We study pretty good quantum state transfer (i.e., state transfer that becomes arbitrarily close to perfect) between vertices of graphs with an involution in the presence of an energy potential. In particular, we show that if a graph has an…

Combinatorics · Mathematics 2017-02-24 Mark Kempton , Gabor Lippner , Shing-Tung Yau

We characterize perfect state transfer on real-weighted graphs of the Johnson scheme $\mathcal{J}(n,k)$. Given $\mathcal{J}(n,k)=\{A_1, A_2, \cdots, A_k\}$ and $A(X) = w_0A_0 + \cdots + w_m A_m$, we show, using classical number theory…

Combinatorics · Mathematics 2020-07-15 Luc Vinet , Hanmeng Zhan

Given a graph $G$ with vertex set $V(G)=\{v_1,v_2,\ldots,v_{n_1}\}$ and a graph $H$ of order $n_2$, the vertex complemented corona, denoted by $G\tilde{\circ}{H}$, is the graph produced by copying $H$ $n_1$ times, with the $i$-th copy of…

Quantum Physics · Physics 2025-02-21 Ke-Yu Zhu , Gui-Xian Tian , Shu-Yu Cui

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, where instead of the adjacency matrix, we take the Laplacian…

Combinatorics · Mathematics 2025-04-17 Hermie Monterde , Hiranmoy Pal , Steve Kirkland

We study the existence of quantum state transfer on non-integral circulant graphs. We find that continuous time quantum walks on quantum networks based on certain circulant graphs with $2^k$ $\left(k\in\mathbb{Z}\right)$ vertices exhibit…

Combinatorics · Mathematics 2019-01-09 Hiranmoy Pal

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…

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

Perfect quantum state transfer is achievable in different settings, including linear qubit chains, bi-dimensional arrays, ladders, etc. The most studied case contemplates transferring arbitrary one-qubit pure states in systems with…

Quantum Physics · Physics 2026-04-06 Pablo Serra , Alejandro Ferrón , Omar Osenda

We study perfect state transfer and multiple state transfer in oriented normal Cayley graphs. We construct examples in a variety of groups, ranging from abelian to nonsolvable, and establish some general restrictions and nonexistence…

Given a graph with Hermitian adjacency matrix $H$, perfect state transfer occurs from vertex $a$ to vertex $b$ if the $(b,a)$-entry of the unitary matrix $\exp(-iHt)$ has unit magnitude for some time $t$. This phenomenon is relevant for…

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

Let A be the adjacency matrix of a graph $X$ and suppose U(t)=exp(itA). We view A as acting on $\cx^{V(X)}$ and take the standard basis of this space to be the vectors $e_u$ for $u$ in $V(X)$. Physicists say that we have perfect state…

Combinatorics · Mathematics 2012-09-03 Xiaoxia Fan , Chris Godsil