Large anisotropy of electron and holegfactors in infrared-emitting InAs/InAlGaAs self-assembled quantum dots

Abstract

A detailed study of the g-factor anisotropy of electrons and holes in InAs/In0.53Al0.24Ga0.23As selfassembled quantum dots emitting in the telecom spectral range of 1.5−1.6 µm (around 0.8 eV photon energy) is performed by time-resolved pump-probe ellipticity technique using a superconducting vector magnet. All components of the g-factor tensors are measured, including their spread in the quantum dot (QD) ensemble. Surprisingly, the electron g factor shows a large anisotropy changing from ge,x = −1.63 to ge,z = −2.52 between directions perpendicular and parallel to the dot growth axis, respectively, at an energy of 0.82 eV. The hole g-factor anisotropy at this energy is even stronger: |g h,x | = 0.64 and |g h,z | = 2.29. On the other hand, the in-plane anisotropies of electron and hole g factors are small. The pronounced out-of-plane anisotropy is also observed for the spread of the g factors, determined from the spin dephasing time. The hole longitudinal g factors are described with a theoretical model that allows us to estimate the QD parameters. We find that the QD height-to-diameter ratio increases while the indium composition decreases with increasing QD emission energy.

Erratum: Quantum model for mode locking in pulsed semiconductor quantum dots [Phys. Rev. B 94 , 245308 (2016)]

“…In particular, it has been suggested that the nuclear Zeeman effect, absent in our model, leads to a significant decrease in the mode-locking rate [53,57]. Further interactions that affect the nuclear dynamics are the quadrupolar interaction of the nuclei (in case they are considered as spin-3 2 particles) [39][40][41][42], the dipoledipole interaction between nuclei [43], and anisotropy of the dipolar hyperfine interaction or of the g factors (in case of a hole central spin rather than an electron) [40,47,[61][62][63][64][65]. The present framework of perturbation theory could be extended with these additional interactions with relatively small effort.…”

Anisotropies of the g-factor tensor and diamagnetic coefficient in crystal-phase quantum dots in InP nanowires

“…The different behavior of both these states with θ can be explained by taking into account the anisotropies of the g-factor tensor and diamagnetic coefficient in presence of an inplane magnetic field. In fact, the variation of g-factor with θ can be described as [23,47,48]: (solid curves in Fig. 5 (a)) and from this we obtain � representing the electron and hole effective mass perpendicular to the applied magnetic field.…”

Consequences of Spin-Orbit Coupling at the Single Hole Level: Spin-Flip Tunneling and the Anisotropic g Factor

“…In Fig. 3(c) we set the dramatic anisotropy demonstrated in our experiment against the measurements in SADs [20] and silicon nanowire hole QDs [21], where the LH subband is confined, and in consequence the hole g-factor does not reach zero for in-plane magnetic field.…”

“…In this regime the strong anisotropy of the hole g-factor is expected [12]. To date, however, only partial anisotropy was demonstrated, e.g., in InAs SADs [20] and silicon nanowires [21]. Holes in GaAs are also subject to strong Dreselhaus and Rashba spin-orbit interactions, which introduce the coherent spin-flip tunneling [12,13].…”