Tuning the Exciton Binding Energies in Single Self-AssembledInGaAs/GaAsQuantum Dots by Piezoelectric-Induced Biaxial Stress

Abstract

We study the effect of an external biaxial stress on the light emission of single InGaAs/GaAs(001) quantum dots placed onto piezoelectric actuators. With increasing compression, the emission blueshifts and the binding energies of the positive trion (X+) and biexciton (XX) relative to the neutral exciton (X) show a monotonic increase. This phenomenon is mainly ascribed to changes in electron and hole localization and it provides a robust method to achieve color coincidence in the emission of X and XX, which is a prerequisite for the possible generation of entangled photon pairs via the recently proposed "time reordering" scheme.

Strain-inducedg-factor tuning in single InGaAs/GaAs quantum dots

“…The effects of strain on the electronic structure of semiconductor nanostructures have been extensively studied in the past, both theoretically and experimentally [12][13][14][15][16]. Therefore it is well known that strain profoundly modifies the band structure in a bulk semiconductor material.…”

“…As discussed in detail in Ref. [13], these small differences can be accounted for by the effects of strain on the confinement potential of electron and holes confined in QDs and, as a consequence, on their Coulomb interaction. In the total range of voltages explored in our experiments (0-500 V), the QD emission lines shift by ∼1 meV.…”

“…Several methods to incorporate strain in a QD layer exist, such as by embedding QDs in a bowed airbridge structure [14] or by integrating the QD layer on piezoelectric material [13,17]. The latter method is applied here.…”

Coherent piezoelectric strain transfer to thick epitaxial ferromagnetic films with large lattice mismatch

“…The most commonly used piezoelectric substrate is (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 , which is a well-known relaxor ferroelectric material with excellent electromechanical and piezoelectric properties for compositions near the morphotropic phase 3 boundary (0.25  x  0.35) [12]. Piezoelectric strain transfer from PMN-PT substrates has, for example, been used to tune the magnetic properties of manganite [13,14], ferrite [15][16][17][18][19], and metallic magnetic films [20][21][22][23], to alter the electrical resistance of magnetic oxides [13,18,[24][25][26], to demonstrate straincontrolled light emission from semiconductor heterostructures [27,28], and to tailor the properties of graphene [29]. In addition, strain-modulation of magnetic properties on a microscopic scale has recently been demonstrated in ferromagnetic-ferroelectric hybrids [30][31][32], which has opened new ways to electric control of ferromagnetic domain formation and magnetic domain wall motion [33,34].…”

Tuning exciton energy and fine-structure splitting in single InAs quantum dots by applying uniaxial stress

“…8 Therefore, the photon entanglement is destroyed. 3,9 Different tuning techniques to erase the FSS, such as thermal annealing, 10 applying electric fields, [11][12][13] magnetic fields, 14 and strain fields [15][16][17][18][19][20][21][22] have been explored. Recently, a new method of using a microstructured semiconductor-piezoelectric device to build scalable entangled photon sources with self-assembled QDs was proposed, 23,24 and was successfully demonstrated by combined uniaxial stresses along two orthogonal directions, i.e., along [110] and [1-10] crystal axis of GaAs.…”