Journal of Quantum Information Science, 2013, 3, 51-56
http://dx.doi.org/10.4236/jqis.2013.32010 Published Online June 2013 (http://www.scirp.org/journal/jqis)
Survival Probability of the Quantum Walk with Phase
Parameters on the Two-Dimensional Trapped Lattice
Clement Ampadu
1
, Meltem Gönülol
2
, Ekrem Aydıner
2
1
31 Carrolton Road, Boston, MA, USA
2
İstanbul University Theoretical Physics Group, Department of Physics, İstanbul University, İstanbul, Turkey
Email: drampadu@hotmail.com, ekrem.aydiner@istanbul.edu.tr
Received March 27, 2013; revised May 5, 2013; accepted May 18, 2013
Copyright © 2013 Clement Ampadu et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
We investigate the time dependence of the survival probability of quantum walks governed by Fibonacci walks with
phase parameters on the trapped two-dimensional lattice. We have shown that the survival probability of the quantum
walk decays with time obey to the stretched exponential law for all initial states of walkers. We have also shown that
stretched exponential decay parameter β can be arranged by phase parameter combination. Obtained numerical results
show that phase parameters can be used as a control parameter to determine the decay rate of the survival probability of
the quantum walk.
Keywords: Quantum Walk; Survival Probability
1. Introduction
In recent years, the quantum walk on the trapped lattice
has been intensively investigated due to importance ap-
plications in quantum information and computing.
Therefore, many theoretical and experimental studies
have been carried out to understand the effect of the
trapping states on the quantum walk. For example,
Agliari [1] considered a continuous-time quantum walk
propagating on Erdos-Renyi random graphs in the pres-
ence of a random distribution of traps, and showed that
the survival probability exhibits an exponential character
which fluctuates depending on the trap concentration.
Zahringer et al. [2] implemented a quantum walk using
trapped ions. They used an experimental technique to
determine the probability distribution along a line in
phase space. It is shown that instabilities in the trapping
frequency leads to decoherence and by change in the
coupling strength due to high phonon numbers. Schimitz
et al. [3] implemented the proof of principle for the
quantum walk of one ion in a linear ion trap. It is shown
that quantum interference enforces asymmetric, non-
classical distributions in the highly entangled degrees of
freedom (of coin and position states). Xue et al. [4] im-
plemented a multi-step quantum walk for a single
trapped ion with interpolation between quantum and
random walk by randomizing the generalized Hadamard
coin flip phase. It is shown that the distribution of the
walker spreads over unbounded position space rather
than being folded back on itself. Agliari et al. [5] studied
the continuous time quantum walk focusing on trapping
processes on a ring and show that when the traps are ar-
ranged periodically the survival probability decays as-
ymptotically, when the traps are arranged to form a clus-
ter the survival probability decays exponentially, on the
other hand for randomly distributed traps the survival
probability decays algebraically. Eckert et al. [6] imple-
mented the quantum walk with a neutral atom trapped in
a ground state of optical potentials by using the concept
of spatially delocalized quibits, that is, a coin defined
through the presence of the atom in one out of two trap-
ping potentials. It is shown that the shaking of the trap
position on the quantum walk leads to a flat distribution
in the transition from quantum to classical in the inter-
mediate. Wojcik et al. [7] studied changing a phase at a
single point in a discrete quantum walk. For certain val-
ues of this phase change and the internal coin-state of the
walker it is shown the distribution exhibits the localiza-
tion phenomenon. Altmann et al. [8] studied chaotic
scattering, it is shown that noise enhances the trapping of
trajectories in scattering systems. In particular, they show
that weak noise leads to a slower decay of the survival
probability. Karksi et al. [9] implemented a quantum
walk on the line with single neutral atoms by determinis-
tically delocalizing them over the sites of a one-dimen-
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