Pauli blockade microscopy of quantum dots

TL;DR

This paper proposes a spin-sensitive microscopy technique for double quantum dots that uses an AC voltage to induce electric spin resonance, enabling the study of spin dynamics and Pauli blockade lifting.

Contribution

It introduces a novel scanning probe method to analyze spin states and transitions in quantum dots under Pauli blockade conditions using an AC voltage.

Findings

Transition rates depend strongly on tip position.

Transition matrix elements align with observed spin-flip rates.

Method enables probing of spin densities and transition states.

Abstract

We propose a spin-sensitive scanning probe microscopy experiment on double quantum dots in Pauli blockade conditions. Electric spin resonance is induced by an AC voltage applied to the scanning gate which induces lifting of the Pauli blockade of the current. The stationary Hamiltonian eigenstates are used as a basis for description of the spin dynamics with the AC potential of the probe. For the two-electron system we evaluate the transitions rates from triplet $\mathrm{T}_+$ state to singlet $\mathrm{S}$ or triplet $\mathrm{T}_0$ states, i.e. to conditions in which the Pauli blockade of the current is lifted. The rates of the spin-flip transitions are consistent with the transition matrix elements and strongly dependent on the tip position. Probing the spin densities and identification of the final transition state are discussed.