Title
Limit theorems for the discrete-time quantum walk on a graph with joined half lines
Abstract
We consider a discrete-time quantum walk Wt,κ at time t on a graph with joined half lines Jκ, which is composed of κ half lines with the same origin. Our analysis is based on a reduction of the walk on a half line. The idea plays an important role to analyze the walks on some class of graphs with symmetric initial states. In this paper, we introduce a quantum walk with an enlarged basis and show that Wt,κ can be reduced to the walk on a half line even if the initial state is asymmetric. For Wt,κ, we obtain two types of limit theorems. The first one is an asymptotic behavior of Wt,κ which corresponds to localization. For some conditions, we find that the asymptotic behavior oscillates. The second one is the weak convergence theorem for Wt,κ. On each half line, Wt,κ converges to a density function like the case of the one-dimensional lattice with a scaling order of t. The results contain the cases of quantum walks starting from the general initial state on a half line with the general coin and homogeneous trees with the Grover coin.
Year
Venue
Keywords
2012
Quantum Information & Computation
half line,asymptotic behavior,quantum walk,symmetric initial state,initial state,general coin,discrete-time quantum walk,asymptotic behavior oscillates,limit theorem,grover coin,general initial state,half lines j,quantum physics,discrete time,localization,oscillations,weak convergence
Field
DocType
Volume
Discrete mathematics,Weak convergence,Combinatorics,Lattice (order),Quantum mechanics,Homogeneous tree,Quantum walk,Discrete time and continuous time,Scaling,Probability density function,Asymptotic analysis,Mathematics
Journal
12
Issue
ISSN
Citations 
3-4
Quantum Information and Computation 12, (2012) 0314--0333
3
PageRank 
References 
Authors
0.84
4
3
Name
Order
Citations
PageRank
Kota Chisaki161.35
Norio Konno212529.90
Etsuo Segawa32710.11