Computing with spins: From classical to quantum computing

TL;DR

This paper reviews the evolution from classical to quantum computing using electron spins in quantum dots, highlighting how spin states encode information and enable logic gate implementation.

Contribution

It provides a concise overview of spin-based computing, emphasizing the transition from classical bits to quantum qubits in quantum dot systems.

Findings

Spin polarization encodes classical bits in quantum dots.

Superposition states enable qubit representation.

Exchange interactions facilitate logic gate operations.

Abstract

This article traces a brief history of the use of single electron spins to compute. In classical computing schemes, a binary bit is represented by the spin polarization of a single electron confined in a quantum dot. If a weak magnetic field is present, the spin orientation becomes a binary variable which can encode logic 0 and logic 1. Coherent superposition of these two polarizations represent a qubit. By engineering the exchange interaction between closely spaced spins in neighboring quantum dots, it is possible to implement either classical or quantum logic gates.