Estimation of the local density of states on a quantum computer

作     者：Joseph Emerson Seth Lloyd David Poulin David Cory 

作者机构：Department of Nuclear Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Institute for Quantum Computing University of Waterloo Waterloo ON Canada N2L 3G1 

出 版 物：《Physical Review A》 (物理学评论A辑：原子、分子和光学物理学)

年 卷 期：2004年第69卷第5期

页      面：050305(R)-050305(R)页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：RANDOM BANDED MATRICES CHARACTERISTIC VECTORS INFINITE DIMENSIONS BORDEREDMATRICES SYSTEMS PARTICLES SPECTRUM ELEMENTS 

摘      要：We report an efficient quantum algorithm for estimating the local density of states (LDOS) on a quantum computer. The LDOS describes the redistribution of energy levels of a quantum system under the influence of a perturbation. Sometimes known as the “strength function from nuclear spectroscopy experiments, the shape of the LDOS is directly related to the survivial probability of unperturbed eigenstates, and has recently been related to the fidelity decay (or “Loschmidt echo) under imperfect motion reversal. For quantum systems that can be simulated efficiently on a quantum computer, the LDOS estimation algorithm enables an exponential speedup over direct classical computation.