1307.7428 (A. Thilagam)

Exciton propagation via quantum walks based on non-Hermitian coin flip
operations    [PDF]

A. Thilagam

We examine the coherent propagation of the one-dimensional Frenkel exciton (correlated electron-hole pair system) based on a model of a quantum walker in multi-dimensional Hilbert space. The walk is governed by a non-Hermitian coin flip operation that is coupled to a generalized shift mechanism. The dissipative coin flip operation is associated with amplitude leakages at an occupied site, typical of processes which occur when an exciton is transferred along dimer sites in photosynthetic protein complexes. We analyze the characteristics probability distribution of the one-dimensional quantum walk for various system parameters, and examine the complex interplay between non-Markovian signatures and amplitude leakages within the Hilbert position subspace. Can topological defects such as exceptional points, and non-Markovian signatures be detected from a time evolving reconstructed excitonic state density matrix using quantum tomography measurements? We examine these possibilities in the broader context of a quantum information theoretic approach to spectroscopic experiments.

View original: http://arxiv.org/abs/1307.7428