Quantum walk on the line with quantum rings

TL;DR

This paper presents a method to implement a one-dimensional quantum walk using electrons in a network of spintronic quantum rings, leveraging tunable spin-orbit interactions for coin and step operations.

Contribution

It introduces a novel physical implementation of quantum walks using spintronic semiconductor devices with controllable spin-orbit coupling.

Findings

Proposes a scheme for quantum walks with electrons in quantum rings.

Demonstrates how to realize coin-toss and step operators via device geometry and spin-orbit interaction.

Provides a tunable platform for experimental quantum walk implementations.

Abstract

We propose a scheme to implement the one-dimensional coined quantum walk with electrons transported through a two-dimensional network of spintronic semiconductor quantum rings. The coin degree of freedom is represented by the spin of the electron, while the discrete position of the walker corresponds to the label of the rings in one of the spatial directions in the network. We assume that Rashba-type spin-orbit interaction is present in the rings, the strength of which can be tuned by an external electric field. The geometry of the device, together with the appropriate spin-orbit interaction strengths, ensure the realization of the coin-toss (i.e. spin-flip) and the step operator.