Quantum and classical mobility determination of the dominant scattering mechanism in the two-dimensional electron gas of an AlGaAs/GaAs heterojunction

Harrang, J.P.; Higgins, R. J.; Goodall, Randal K.; Jay, P.R.; Laviron, M.; Delescluse, P.

doi:10.1103/physrevb.32.8126

Cited by 210 publications

(114 citation statements)

References 17 publications

Supporting

Mentioning

106

Contrasting

Unclassified

Order By: Relevance

“…in silicon MOSFETs), but for long range Coulomb interactions (e.g. from modulation doping) τ t and τ q are quite different [16,17,18]. The difference lies in the fact that τ q counts all scattering events, while τ t is weighted towards large-angle scattering events that cause a significant change in the momentum.…”

Section: Introductionmentioning

confidence: 99%

“…It is widely assumed that the ratio of the transport to the single particle lifetime τ t /τ q can be taken as an indication of the dominant scattering mechanism [16,17,18,19]. The conventional wisdom is that τ t /τ q should be close to 1 for background impurity scattering and much larger than 1 for remote ionised impurity scattering.…”

Section: B Comparison Of τT/τqr and τT/τqmentioning

confidence: 99%

“…The difference lies in the fact that τ q counts all scattering events, while τ t is weighted towards large-angle scattering events that cause a significant change in the momentum. By comparing the measured τ t and τ q with numerical calculations it is possible to determine the nature of the predominant scattering mechanism in a 2DEG at low temperatures [16,17,18,19]. This is particularly important for background impurity scattering in ultra-high mobility 2D systems, since the impurity levels are so low that they cannot be measured by direct tools such as deep level transient spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Role of background impurities in the single-particle relaxation lifetime of a two-dimensional electron gas

et al. 2009

View full text Add to dashboard Cite

We re-examine the quantum τq and transport τt scattering lifetimes due to background impurities in two-dimensional systems. We show that the well-known logarithmic divergence in the quantum lifetime is due to the non-physical assumption of an infinitely thick heterostructure, and demonstrate that the existing non-divergent multiple scattering theory can lead to unphysical quantum scattering lifetimes in high quality heterostructures. We derive a non-divergent scattering lifetime for finite thickness structures, which can be used both with lowest order perturbation theory and the multiple scattering theory. We calculate the quantum and transport lifetimes for electrons in generic GaAsAlGaAs heterostructures, and find that the correct 'rule of thumb' to distinguish the dominant scattering mechanisms in GaAs heterostructures should be τt/τq 10 for background impurities and τt/τq 10 for remote impurities. Finally we present the first comparison of theoretical results for τq and τt with experimental data from a GaAs 2DEG in which only background impurity scattering is present. We obtain excellent agreement between the calculations and experimental data, and are able to extract the background impurity density in both the GaAs and AlGaAs regions.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: B Comparison Of τT/τqr and τT/τqmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Role of background impurities in the single-particle relaxation lifetime of a two-dimensional electron gas

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The lifetime damping rate is the measure of the rate at which particles scatters out of an eigenstate, whereas the transport scattering rate is a measure of the rate of current decay due to scattering out of an eigenstate. In normal 2DEGs, the transport scattering time can be much larger than the impurity induced lifetime /2γ, particularly in high mobility modulation doped 2D systems where the charged impurities are placed very far from the 2DEG 8,9 . Recently, the issue of transport scattering time versus impurity scattering lifetime in graphene has been discussed.…”

Section: Introductionmentioning

confidence: 99%

“…In the presence of scattering from an impurity potential that is not diagonal in the these eigenstates, the lifetime scattering rate of the eigenstate, γ, is non-zero and can be measured experimentally by fitting the line-shape of the low-field Shubnikov-de Haas (SdH) oscillations. 7,8 The effect of disorder scattering on the SdH line shape is equivalent to increasing the sample temperature and one can therefore measure this Dingle temperature (T D ) and relate it to the single-particle lifetime through γ = 2πk B T D . To avoid potential confusion, we mention that the lifetime damping rate γ discussed in this paper is not equal to the transport scattering rate which governs the electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

Density of states of disordered graphene

Hwang

Sarma

2008

Phys. Rev. B

View full text Add to dashboard Cite

We calculate the average single particle density of states in graphene with disorder due to impurity potentials. For unscreened short-ranged impurities, we use the non-self-consistent and self-consistent Born and T -matrix approximations to obtain the self-energy. Among these, only the self-consistent T -matrix approximation gives a non-zero density of states at the Dirac point. The density of states at the Dirac point is non-analytic in the impurity potential. For screened short-ranged and charged long-range impurity potentials, the density of states near the Dirac point typically increases in the presence of impurities, compared to that of the pure system.

show abstract

The Nonlinear Effects in 2DEG Conductivity Investigation by an Acoustic Method

Drichko

Diakonov

Kagan

et al. 1998

phys. stat. sol. (b)

View full text Add to dashboard Cite

The parameters of two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure were determined by an acoustical (contactless) method in the delocalized electrons region (B ≤2.5T).Nonlinear effects in Surface Acoustic Wave (SAW) absorption by 2DEG are determined by the electron heating in the electric field of SAW, which may be described in terms of electron temperature T e . The energy relaxation time τ ǫ is determined by the scattering at piezoelectric potential of acoustic phonons with strong screening. At different SAW frequencies the heating depends on the relationship between ωτ ǫ and 1 and is determined either by the instantaneously changing wave field (ωτ ǫ < 1), or by the average wave power (ωτ ǫ > 1). 72.50, 73.40.

show abstract

Quantum and classical mobility determination of the dominant scattering mechanism in the two-dimensional electron gas of an AlGaAs/GaAs heterojunction

Cited by 210 publications

References 17 publications

Role of background impurities in the single-particle relaxation lifetime of a two-dimensional electron gas

Role of background impurities in the single-particle relaxation lifetime of a two-dimensional electron gas

Density of states of disordered graphene

The Nonlinear Effects in 2DEG Conductivity Investigation by an Acoustic Method

Contact Info

Product

Resources

About