abstract: Quantum walks, while interesting from a fundamental physical perspective, are also known for the applications in realising quantum information protocols, with the most famous probably being the use of the Grover walk to implement the Grover search algorithm.
In this presentation I will show that a quantum walk process can also be used to construct a secure quantum memory. More precisely, I will introduce the idea that a localized quantum walk with temporal disorder can be engineered to store the information of a single qubit on a compact position space and faithfully recover it on demand. Since the localization happens over a finite spread in position space, the stored information will naturally possess a degree of security against and attach from simple eavesdropper, on top of which cryptographic safety can be imposed. The presented protocol can be adopted to any quantum system for which experimental control over quantum walk dynamics can be achieved and is a rare example of a dynamical process used for the purpose of a memory.
C. M. Chandrashekar and Th. Busch
Quantum Systems Unit Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan