Optically tunable nuclear magnetic resonance in a single quantum dot

TL;DR

This paper demonstrates optically controlled nuclear magnetic resonance in single quantum dots, enabling position-selective nuclear spin control and providing insights into electron wave-function distribution.

Contribution

It introduces a method for optically tuning NMR lineshapes in quantum dots, revealing new ways to control and analyze nuclear spins at the nanoscale.

Findings

Optically controlled shifts in NMR peaks in quantum dots.

Asymmetric NMR lineshapes depend on optical excitation conditions.

Potential to measure electron wave-function volume and atom distribution.

Abstract

We report optically detected nuclear magnetic resonance (ODNMR) measurements on small ensembles of nuclear spins in single GaAs quantum dots. Using ODNMR we make direct measurements of the inhomogeneous Knight field from a photo-excited electron which acts on the nuclei in the dot. The resulting shifts of the NMR peak can be optically controlled by varying the electron occupancy and its spin orientation, and lead to strongly asymmetric lineshapes at high optical excitation. The all-optical control of the NMR lineshape will enable position-selective control of small groups of nuclear spins in a dot. Our calculations also show that the asymmetric NMR peak lineshapes can provide information on the volume of the electron wave-function, and may be used for measurements of non-uniform distributions of atoms in nano-structures.