Theoretical limit of mobility of two-dimensional electrons in GaAs

Karpus, V.

doi:10.1088/0268-1242/5/7/009

Cited by 50 publications

(41 citation statements)

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“…The dependence is found to be in an agreement with the theory [43][44][45][46] and direct measurements of the inelastic rate at zero magnetic field 47 . In contrast, thermopower measurements of the electron temperature shows a strong T 3 increase of the inelastic relaxation rate at zero magnetic field, coexisting with the 1/τ SdH in ∼ T on the same sample and at the same temperatures 19 .…”

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confidence: 82%

“…Within an order of magnitude the cubic term agrees with the one seen in the thermopower experiments 19 . We attribute the T 2 term to e − e scattering 1,2 and the T 3 dependence to the electron-phonon scattering due to the unscreened deformation potential in BG regime 46,48 . The considerable disagreement with the SdH results indicates, thus, an incompleteness of the accepted interpretation of dc biased SdH oscillations 8,14,19 .…”

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confidence: 99%

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Dynamics of quantal heating in electron systems with discrete spectra

et al. 2015

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confidence: 82%

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confidence: 99%

Dynamics of quantal heating in electron systems with discrete spectra

et al. 2015

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“…This relation corresponds to the intermediate temperature range between the Bloch-Gruneisen, T < T 0 , and the linear, T > T 0 , regimes, for the case of non-screened phonon scattering. (The criterion T < T 0 /π [13] for the screened phonon scattering is not satisfied for the majority of our data.) One can see that at the highest p, phonon scattering can fully explain the experimental dependence ρ(T ).…”

mentioning

confidence: 63%

“…In Fig. 1 (c,d), curves ρ(T ) for different densities are plotted together with the theoretical dependence presented as ρ(T ) = ρ 0 + ρ ph , where ρ 0 = σ −1 0 = ρ (T = 0) is the residual resistivity due to impurity scattering, obtained by extrapolation to T = 0, and ρ ph is the result of the calculations for the phonon scattering in GaAs heterostructures [12]. The latter is represented as ρ ph (T ) = a(T /T0) 3 1+c(T /T0) 2 , where parameters a and c depend on the carrier density, effective mass and crystal properties, and T 0 = k −1 B 2m * S 2 t E F , where S t is the transverse sound velocity.…”

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confidence: 99%

Hole-Hole Interaction Effect in the Conductance of the Two-Dimensional Hole Gas in the Ballistic Regime

et al. 2002

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On a high mobility two-dimensional hole gas (2DHG) in a GaAs/GaAlAs heterostructure we study the interaction correction to the Drude conductivity in the ballistic regime, kBT τ /h > 1. It is shown that the 'metallic' behaviour of the resistivity (dρ/dT > 0) of the low-density 2DHG is caused by hole-hole interaction effect in this regime. We find that the temperature dependence of the conductivity and the parallelfield magnetoresistance are in agreement with this description, and determine the Fermi-liquid interaction constant F σ 0 which controls the sign of dρ/dT .It is well known that electron-electron interaction gives rise to a quantum correction to the classical (Drude) conductivity caused by impurity scattering [1]. Its manifestation can be quite different in the two regimes which relate the quasi-particle interaction time,h/k B T , to momentum relaxation time, τ : diffusive (k B T τ /h < 1), and ballistic (k B T τ /h > 1). So far the interaction correction to the conductivity of two-dimensional (2D) systems has been studied, both theoretically and experimentally, only in the diffusive regime, which is applicable to lowmobility (small τ ) systems [1]. Experimentally, the interaction correction was seen to be negative and produce a logarithmic decrease of the resistivity with increasing temperature, similar to the interference correction due to weak localisation (WL). Theory, however, suggests that the sign of the interaction effect in the diffusive regime can be different, dependent on the value of the interaction constant F σ 0 . Thus the correction can become positive and give rise to a 'metallic' temperature dependenceThe role of interactions in the conductance of 2D systems has now been intensely discussed, after the observation of the'metallic' behaviour in some low-density, highmobility 2D systems [3]. If one attempts to apply the conventional interaction theory, it can be seen that in high mobility structures the diffusion approximation becomes invalid even at low T . Recently, a theory of the interaction correction in the ballistic and intermediate regimes has been developed [4]. Stimulated by this theory, in this work we examine the role of the hole-hole interaction effects in a 2D hole gas (2DHG) which shows a 'metallic' ρ(T ). We analyse the temperature dependence of the conductivity and positive magnetoresistance in parallel field, and show that these two main features of the 'metallic' state can be explained by the interaction effect. It has the same origin as the logarithmic correction studied earlier [1], but now manifests itself in the ballistic regime.The interaction theory [4] considers elastic (coherent) electron scattering on the modulated density of other electrons (Friedel oscillation) caused by an impurity with a short-range potential. The phase of the Friedel oscillation, ∆p ∝ exp(i2k F r), is such that the wave scattered from the impurity interferes constructively with the wave scattered from the oscillation, Fig. 1 (a), leading to the quantum correction to the Drude conductivity σ...

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“…The further evidence of this has been obtained from the analysis of the temperature dependence τ −1 ϕ (T ) of the dephasing rate. Estimations show that the contribution to τ −1 ϕ (T ) of electron-phonon scattering [12] is negligible in the studied temperature range. According to the Fermi-liquid theory [15,13,7], the dephasing rate due to electron-electron scattering is dominated either by a linear or quadratic term, dependent on the parameter τ k B T /h:…”

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confidence: 86%

Fermi-Liquid Behavior of the Low-Density 2D Hole Gas in aGaAs/AlGaAsHeterostructure at Large Values ofrs

et al. 2001

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We examine the validity of the Fermi-liquid description of the dilute 2D hole gas in the crossover from 'metallic'-to-'insulating' behaviour of ρ(T ). It has been established that, at rs as large as 29, negative magnetoresistance does exist and is well described by weak localisation. The dephasing time extracted from the magnetoresistance is dominated by the T 2 -term due to Landau scattering in the clean limit. The effect of hole-hole interactions, however, is suppressed when compared with the theory for small rs.

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Theoretical limit of mobility of two-dimensional electrons in GaAs

Abstract: The acoustic phonon limited mobility of two-dimensional electrons in an (001)AIGaAslGaAs heterojunction is calculated. It exceeds the highest experimentally achieved value of mobility by approximately six times at the liquid helium temperature.

Cited by 50 publications

References 6 publications

Dynamics of quantal heating in electron systems with discrete spectra

Dynamics of quantal heating in electron systems with discrete spectra

Hole-Hole Interaction Effect in the Conductance of the Two-Dimensional Hole Gas in the Ballistic Regime

Fermi-Liquid Behavior of the Low-Density 2D Hole Gas in aGaAs/AlGaAsHeterostructure at Large Values ofrs

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