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Related papers: Perfect state transfer on quotient graphs

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We introduce and study peak state transfer, a notion of high state transfer in qubit networks modeled by continuous-time quantum walks. Unlike perfect or pretty good state transfer, peak state transfer does not require fidelity arbitrarily…

Quantum Physics · Physics 2025-10-02 Gabriel Coutinho , Krystal Guo , Vincent Schmeits

We completely characterize circulant graphs with valency up to $4$ that admit perfect state transfer. Those of valency $3$ do not admit it. On the other hand, circulant graphs with valency $4$ admit perfect state transfer only in two…

Combinatorics · Mathematics 2024-11-08 Sho Kubota , Kiyoto Yoshino

In this paper, we consider a continuous-time quantum walk based search algorithm. We introduce equitable partition of the graph and perfect state transfer on it. By these two methods, we can calculate the success probability and the finding…

Quantum Physics · Physics 2022-09-19 Yusuke Ide , Akihiro Narimatsu

A duality between the properties of many spinor bosons on a regular lattice and those of a single particle on a weighted graph reveals that a quantum particle can traverse an infinite hierarchy of networks with perfect probability in…

Quantum Physics · Physics 2009-11-13 David L. Feder

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

We show a perfect state transfer of an arbitrary unknown two-qubit state can be achieved via a discrete-time quantum walk with various settings of coin flippings, and extend this method to distribution of an arbitrary unknown multi-qubit…

Quantum Physics · Physics 2014-07-23 Xiang Zhan , Hao Qin , Zhi-hao Bian , Jian Li , Peng Xue

Let $G$ be a graph with adjacency matrix $A$. The transition matrix of $G$ relative to $A$ is defined by $H_{A}(t):=\exp{(-itA)},\;t\in\Rl$. We say that the graph $G$ admits perfect state transfer between the verteices $u$ and $v$ at…

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

We consider quantum state transfer on finite graphs which are attached to infinite paths. The finite graph represents an operational quantum system for performing useful quantum information tasks. In contrast, the infinite paths represent…

Quantum Physics · Physics 2022-11-30 Pierre-Antoine Bernard , Christino Tamon , Luc Vinet , Weichen Xie

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

The unitary Cayley graph has vertex set $\{0,1, \hdots ,n-1\}$, where two vertices $u$ and $v$ are adjacent if $\gcd(u - v, n) = 1$. In this paper, we study periodicity and perfect state transfer of Grover walks on the unitary Cayley…

Combinatorics · Mathematics 2024-06-26 Koushik Bhakta , Bikash Bhattacharjya

In this paper we study the spectral features, on fractal-like graphs, of Hamiltonians which exhibit the special property of perfect quantum state transfer: the transmission of quantum states without dissipation. The essential goal is to…

Mathematical Physics · Physics 2021-08-04 Gamal Mograby , Maxim Derevyagin , Gerald V. Dunne , Alexander Teplyaev

Quantum state transfer, first introduced by Bose in 2003, is an important physical phenomenon in quantum networks, which plays a vital role in quantum communication and quantum computing. In 2004, Christandl et al. proposed the concept of…

Combinatorics · Mathematics 2025-09-24 Ming Jiang , Xiaogang Liu , Jing Wang

If $X$ is a graph with adjacency matrix $A$, then we define $H(t)$ to be the operator $\exp(itA)$. We say that we have perfect state transfer in $X$ from the vertex $u$ to the vertex $v$ at time $\tau$ if the $uv$-entry of…

Combinatorics · Mathematics 2017-06-20 Chris Godsil

Let $X$ be a graph on $n$ vertices with with adjacency matrix $A$ and let $H(t)$ denote the matrix-valued function $\exp(iAt)$. If $u$ and $v$ are distinct vertices in $X$, we say perfect state transfer from $u$ to $v$ occurs if there is a…

Combinatorics · Mathematics 2011-01-05 Chris Godsil

In this paper, we analyze state transfer in quantum walks by using combinatorial methods. We generalize perfect state transfer in two-reflection discrete-time quantum walks to a notion that we call 'peak state transfer'; we define peak…

Combinatorics · Mathematics 2025-01-14 Krystal Guo , Vincent Schmeits

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

Let $G$ be a graph with adjacency matrix $A$. The transition matrix of $G$ relative to $A$ is defined by $H(t):=\exp{\left(-itA\right)},\;t\in\Rl$. The graph $G$ is said to admit pretty good state transfer between a pair of vertices $u$ and…

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

We examine conditions for a pair of strongly cospectral vertices to have pretty good quantum state transfer in terms of minimal polynomials, and provide cases where pretty good state transfer can be ruled out. We also provide new examples…

Quantum Physics · Physics 2020-10-15 Christopher M. van Bommel

The paper investigates perfect state transfer (PST) in Grover walks on Cayley graphs over the dihedral group $D_n$. The Grover walk is a discrete-time quantum walk widely studied in quantum information processing. A Cayley graph…

Combinatorics · Mathematics 2026-05-05 Koushik Bhakta , Bikash Bhattacharjya , Xiwang Cao

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