Localized quantum walks as secured quantum memory

Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University Okinawa 904-0495, Japan

Received: 11 September 2014
Accepted: 31 March 2015

Abstract

We show that a quantum walk process can be used to construct and secure quantum memory. More precisely, we show that a localized quantum walk with temporal disorder can be engineered to store the information of a single, unknown qubit on a compact position space and faithfully recover it on demand. Since the localization occurs with a finite spread in position space, the stored information of the qubit will be naturally secured from the simple eavesdropper. Our protocol can be adopted to any quantum system for which experimental control over quantum walk dynamics can be achieved.