Mapping Spin Interactions from Conductance Peak Splitting in Coulomb Blockade

TL;DR

This paper presents a theoretical method to extract detailed spin interaction parameters from conductance measurements in quantum dots, enabling magnetic and exchange properties to be inferred from transport data.

Contribution

It introduces a mapping technique linking conductance peak signatures to spin Hamiltonian parameters using a quantum dot system.

Findings

Signatures of multi-spin interactions appear in steady-state conductance.

The method allows measurement of magnetic anisotropy and exchange couplings.

Predictions enable characterization of spin systems using only conductance data.

Abstract

We investigate the transport properties of a quantum dot coupled to leads interacting with a multi-spin system using the generalized master equation within the Coulomb blockade regime. We find that if two states for each scattering region electron manifold are included, several signatures of the interacting spin system appear in steady-state transport properties. We provide a theoretical mapping of differential conductance peak signatures and all spin Hamiltonian parameters related to the inclusion of excited state transitions between uncharged and charged electron manifolds. Our predictions describe a scheme of only using a quantum dot and differential conductance to measure magnetic anisotropy, inter-spin exchange coupling, exchange coupling between the spin system and itinerant electron, and applied magnetic field response.