Maximal coin-position entanglement generation in a quantum walk for the third step and beyond regardless of the initial state

Autor: Xiao-Xu Fang, Kui An, Bai-Tao Zhang, Barry C. Sanders, He Lu
Rok vydání: 2023
Předmět:
Zdroj: Physical Review A. 107
ISSN: 2469-9934
2469-9926
DOI: 10.1103/physreva.107.012433
Popis: We study maximal coin-position entanglement generation via a discrete-time quantum walk, in which the coin operation is randomly selected from one of two coin operators set at each step. We solve maximal entanglement generation as an optimization problem with quantum process fidelity as the cost function. Then we determine the maximal entanglement that can be rigorously generated for any step beyond the second regardless of initial condition with appropriate coin sequences. The simplest coin sequence comprising Hadamard and identity operations is equivalent to the generalized elephant quantum walk, which exhibits an increasingly faster spreading in terms of probability distribution. Experimentally, we demonstrate a ten-step quantum walk driven by such coin sequences with linear optics, and thereby show the desired high-dimensional bipartite entanglement as well as the transport behavior of faster spreading.
13 pages, 6 figures. Comments are welcome
Databáze: OpenAIRE