{ "id": "1501.04396", "version": "v1", "published": "2015-01-19T06:10:30.000Z", "updated": "2015-01-19T06:10:30.000Z", "title": "Perfect state transfer in products and covers of graphs", "authors": [ "Gabriel Coutinho", "Chris Godsil" ], "comment": "15 pages", "categories": [ "math.CO", "quant-ph" ], "abstract": "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, transfer of state among such qubits throughout time can be formalized as the action of the continuous-time quantum walk operator in the characteristic vectors of the vertices. Here we are concerned with the problem of determining which graphs admit a perfect transfer of state. More specifically, we will study graphs whose adjacency matrix is a sum of tensor products of $01$-matrices, focusing on the case where a graph is the tensor product of two other graphs. As a result, we will construct many new examples of perfect state transfer.", "revisions": [ { "version": "v1", "updated": "2015-01-19T06:10:30.000Z" } ], "analyses": { "keywords": [ "perfect state transfer", "tensor product", "continuous-time quantum walk operator", "adjacency matrix", "qubits throughout time" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150104396C" } } }