QC233 : Quantum Walk on Circles and its properties
Thesis > Central Library of Shahrood University > Physics > MSc > 2014
Authors:
Abstarct: In the first chapter we introduce Classical Random Walk (CRW). Probability
distribution, standard deviation and diffusion factor are some parameters of CRW
will be studied in the same chapter. Then the chapter will continue with Quantum
Walk on Line (QWL) and introduce evolution operator for QWL and studying its
effect on the walker’s state. It is useful to compare probability distribution and
variance of QWL with the classical one. Fourier transform would be an appropri
ate tool to map the evolution operator into k space to calculate eigenvalues and
eigenvectors of the evolution opertor of quantum walk on line.
Chapter 2 introduces another model of quantum walk known as Quantum Walk
on a Cycle. We introduce necessary modifications to 1DQW operators to be used
in Quantum Walk on a Cycle. The chapter will describe how to solve eigenvalue
problems for the operator. Limiting Distribution is an important concept which
is introduced and investigated in different situations in this chapter. Mixing Time
is another concept to be defined in the chapter and we are going to find an upper
bound for it.
In the last chapter, we will present our model of quantum walk on a cycle, namely
Mobius Quantum Walk. Indeed this is a modification to the previous model,
i.e. quantum walk on a cycle. In our model, quantum walk on a cycle has been
modified by introducing some kind of rotation around the track on the cycle, char
acterized by the parameter α. The chapter shows that α and the extended space
for the rotation improve the parameters including limiting distribution and mixing
time. We also study the changes made by α in eigenvalues and eigenvectors and
the way it affects degeneracy, so we find out how it affects different parameters
such as limiting distribution or mixing time. Finally, it is possible to assume that
the space for rotation and the spin pace are entangled, which is shown to improve
limiting distribution.
Keywords:
#
Keeping place: Central Library of Shahrood University
Visitor:
Keeping place: Central Library of Shahrood University
Visitor: