Exploring exchange mechanisms with a cold atom gas

TL;DR

This paper investigates exchange mechanisms using a cold atom gas, demonstrating how few-fermion systems can simulate complex magnetic interactions and quantum entanglement.

Contribution

It introduces minimal models of exchange mechanisms with trapped fermions, providing a quantum simulation platform for magnetic phenomena and entanglement manipulation.

Findings

Two fermions model the direct exchange mechanism.

Three atoms simulate the double exchange mechanism.

The system can create, manipulate, and detect quantum entanglement.

Abstract

Fermionic atoms trapped in a double well potential are an ideal setting to study fundamental exchange mechanisms. We use exact diagonalization and complementary analytic calculations to demonstrate that two trapped fermions deliver a minimal model of the direct exchange mechanism. This is an ideal quantum simulator of the Heisenberg antiferromagnet, exposes the competition between covalent and ionic bonding, and can create, manipulate, and detect quantum entanglement. Three trapped atoms form a faithful simulator of the double exchange mechanism that is the fundamental building block behind many Heisenberg ferromagnets.