Origin of disorder in self-ordered GaAs/AlGaAs quantum wires grown by OMVPE on V-grooved substrate

Lelarge, F.; Otterburg, T.; Oberli, D. Y.; Rudra, A.; Kapon, E.

doi:10.1016/s0022-0248(00)00776-4

Cited by 7 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, during the growth of low-dimensional structures, interfacial roughness develops due to misorientation with the substrate, 2 and monolayer (ML) fluctuations. 3 This results in the localization of excitons at low temperatures. 4,5 In 1D wires these width fluctuations lead to the formation of quasi-0D quantum boxes along the wire axis, 6 the effects of which have been observed in µPL measurements 7,8,9 and exciton radiative lifetimes.…”

Section: Introductionmentioning

confidence: 99%

Carrier relaxation inGaAsv-groove quantum wires and the effects of localization

et al. 2004

View full text Add to dashboard Cite

Carrier relaxation processes have been investigated in GaAs/AlGaAs v-groove quantum wires (QWRs) with a large subband separation (∆E ≃ 46 meV). Signatures of inhibited carrier relaxation mechanisms are seen in temperature-dependent photoluminescence (PL) and photoluminescenceexcitation (PLE) measurements; we observe strong emission from the first excited state of the QWR below ∼50 K. This is attributed to reduced inter-subband relaxation via phonon scattering between localized states. Theoretical calculations and experimental results indicate that the pinchoff regions, which provide additional two-dimensional confinement for the QWR structure, have a blocking effect on relaxation mechanisms for certain structures within the v-groove. Time-resolved PL measurements show that efficient carrier relaxation from excited QWR states into the ground state, occurs only at temperatures > ∼ 30 K. Values for the low temperature radiative lifetimes of the ground-and first excited-state excitons have been obtained (340 ps and 160 ps respectively), and their corresponding localization lengths along the wire estimated.

show abstract

Section: Introductionmentioning

confidence: 99%

Carrier relaxation inGaAsv-groove quantum wires and the effects of localization

et al. 2004

View full text Add to dashboard Cite

show abstract

“…As was mentioned in our previous work, 17 the disorder in V-groove QWRs stems mainly from interface roughness brought about by lithography imperfections on the patterned substrate and peculiar faceting taking place during MOVPE on a nonplanar surface. 26 The specific features of the disorder in the QWRs studied here, in terms of the depth and size of the localization potential, are expected to vary from sample to sample. Thus, for our devices averaging on the disorder parameters takes place since we measure many QWRs in parallel.…”

Section: Sample Preparation and The Measurement Setupmentioning

confidence: 98%

Experimental evidence for Luttinger liquid behavior in sufficiently long GaAs V-groove quantum wires

et al. 2012

View full text Add to dashboard Cite

We have measured the temperature dependence of the conductance of long V-groove quantum wires fabricated using GaAs/AlGaAs heterostructures, in a wide temperature range (200 mK < T < 4.2 K). We find that for our quantum wires the Fermi velocity can be as low as v F ∼ = 5 × 10 4 m/s, corresponding to an interaction parameter value of g ∼ = 0.56. This value suggests that our data are consistent with theories developed within the framework of the Luttinger liquid model in the presence of a single strong barrier (weak link).

show abstract

“…Disorder in V-groove QWRs stems mainly from interface roughness brought about by lithography imperfections on the patterned substrate and peculiar faceting taking place during MOVPE on a nonplanar surface [22]. The disorder results in potential fluctuations along the axis of the wire, and manifests itself in localization of excitons and other charge carriers as evidenced in optical spectroscopy studies of these wires [23].…”

mentioning

confidence: 99%

Luttinger-Liquid Behavior in Weakly Disordered Quantum Wires

et al. 2006

View full text Add to dashboard Cite

We have measured the temperature dependence of the conductance in long V-groove quantum wires (QWRs) fabricated in GaAs/AlGaAs heterostructures. Our data is consistent with recent theories developed within the framework of the Luttinger liquid model, in the limit of weakly disordered wires. We show that for the relatively low level of disorder in our QWRs, the value of the interaction parameter g ∼ = 0.66, which is the expected value for GaAs. However, samples with a higher level of disorder show conductance with stronger temperature dependence, which does not allow their treatment in the framework of perturbation theory. Fitting such data with perturbation-theory models leads inevitably to wrong (lower) values of g. The electrical conductance through noninteracting clean quantum wires (QWRs) containing a number of one-dimensional subbands is quantized in the universal unit, as observed in narrow constrictions in 2D electron gas (2DEG) systems [2,3]. For such short and clean narrow wires, the e-e interactions described by the so-called Luttinger liquid (LL) model [4] do not affect the value of the conductance, namely it is temperature and length independent as indeed was shown experimentally [2,3]. In the presence of disorder in sufficiently long QWRs, suppression of the conductance is expected at low temperatures. A number of theoretical papers addressing this issue [5,6,7,8] predict a negative correction to the conductance versus temperature G(T ), which increases with T and obeys a power law: T g−1 , where g < 1 is an interaction parameter.The validity of the implications of the LL theory has been recently demonstrated in a number of experiments [9,10]. The most evident proofs of the predictions were shown in tunnelling experiments performed in T-shaped cleaved-edged overgrown GaAs quantum wires [9] and in carbon nanotubes [10]. Earlier non-tunnelling experiments, in which suppression of conductance occurs in the linear response regime, did not unambiguously prove the validity of the theory, and the value of the g parameter could not be deduced from the experimental data [11,12,13]. Several complications are encountered in such experiments. For sufficiently disordered wires, where the correction to G(T ) is expected to be large, the value of the conductance at the plateau is not well defined due to the specific realization of the disordered potential in the wire, as was the case for the long wires of Tarucha et al. [11]. Moreover, in the intermediate regime, namely for disorder level for which the conductance plateau could be well defined but the corrections to G(T ) are already significant for a relatively narrow temperature range, g cannot be extracted by applying a perturbation theory. If however, the disorder is very weak so that the plateaus are well defined at all temperatures [11,12], the variation of its value versus temperature is so weak that the g parameter cannot be reliably determined. Therefore, if one wishes to compare G(T ) to the theory, a wire possessing just the right amount of disorder is ...

show abstract

Origin of disorder in self-ordered GaAs/AlGaAs quantum wires grown by OMVPE on V-grooved substrate

Cited by 7 publications

References 13 publications

Carrier relaxation inGaAsv-groove quantum wires and the effects of localization

Carrier relaxation inGaAsv-groove quantum wires and the effects of localization

Experimental evidence for Luttinger liquid behavior in sufficiently long GaAs V-groove quantum wires

Luttinger-Liquid Behavior in Weakly Disordered Quantum Wires

Contact Info

Product

Resources

About