{ "id": "1508.07473", "version": "v1", "published": "2015-08-29T16:22:18.000Z", "updated": "2015-08-29T16:22:18.000Z", "title": "Generator of an abstract quantum walk", "authors": [ "Etuso Segawa", "Akito Suzuki" ], "categories": [ "math-ph", "math.MP", "math.SP" ], "abstract": "We consider an abstract quantum walk defined by a unitary evolution operator $U$, which acts on a Hilbert space decomposed into a direct sum of Hilbert spaces $\\{\\mathcal{H}_v \\}_{v \\in V}$. We show that such $U$ naturally defines a directed graph $G_U$ and the probability of finding a quantum walker on $G_U$. The asymptotic property of an abstract quantum walker is governed by the generator $H$ of $U$ such that $U^n = e^{inH}$. We derive the generator of an evolution of the form $U = S(2d_A^* d_A -1)$, a generalization of the Szegedy evolution operator. Here $d_A$ is a boundary operator and $S$ a shift operator.", "revisions": [ { "version": "v1", "updated": "2015-08-29T16:22:18.000Z" } ], "analyses": { "subjects": [ "81S25", "81P68", "82B41" ], "keywords": [ "hilbert space", "szegedy evolution operator", "unitary evolution operator", "abstract quantum walker", "direct sum" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150807473S" } } }