Magneto-optical characterization of trions in symmetric InP-based quantum dots for quantum communication applications

TL;DR

This study measures magneto-optical properties of trions in large, symmetric InP-based quantum dots with emission in the telecom window, revealing anisotropic diamagnetic shifts and small g-factors suitable for quantum communication and spin control.

Contribution

It provides novel magneto-optical characterization data of trions in InP quantum dots grown by molecular beam epitaxy, highlighting their potential for quantum communication applications.

Findings

Diamagnetic coefficients range: 1.5-4 μeV/T² (out-of-plane), 8-15 μeV/T² (in-plane).

Trion g-factors are small, 0.3-0.7 and 0.5-1.3, in different configurations.

Dots show promise for electrical g-factor tuning for qubit control.

Abstract

Magneto-optical parameters of trions in novel large and symmetric InP-based quantum dots, uncommon for molecular beam epitaxy grown nanostructures, with emission in the third telecom window, are measured in Voigt and Faraday configurations of external magnetic field. The diamagnetic coefficients are found to be in the range of 1.5-4 {\mu}eV/{\T^2}, and 8-15 {\mu}eV/{\T^2}, respectively out of plane and in plane of the dots. The determined values of diamagnetic shifts are related to the anisotropy of dot sizes. Trion g-factors are measured to be relatively small, in the range of 0.3-0.7 and 0.5-1.3, in both configurations respectively. Analysis of single carrier g-factors, based on the formalism of spin-correlated orbital currents, leads to the similar values for hole and electron of {\sim} 0.25 for Voigt and {\g_e} {\approx} -5; {\g_h} {\approx} +6 for Faraday configuration of magnetic field. Values of g-factors close to zero measured in Voigt configuration make the investigated dots promising for electrical tuning of g-factor sign, required for schemes of single spin control in qubit applications.