Resistance noise scaling in a dilute two-dimensional hole system in GaAs

Leturcq, R.; Deville, G.; L’Hôte, D.; Tourbot, R.; Mellor, C.J.; Henini, M.

doi:10.1117/12.546505

Cited by 3 publications

(2 citation statements)

References 86 publications

(198 reference statements)

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“…1). The qualitative agreement between our theoretical results and the experimental 2D MIT data is prima facie evidence that our proposed physical mechanism is likely to be playing a role (perhaps even a major role) in the underlying physics of 2D MIT phenomena [7][8][9][10][11][12]15,18,19,[21][22][23][26][27][28][29] . We cannot, however, rule out (certainly, not conclusively) the possibility of alternate physical mechanisms also playing some role in the 2D MIT phenomena since our model is based only on the single physical mechanism described in this work.…”

Section: Introductionsupporting

confidence: 70%

Two-dimensional metal-insulator transition as a potential fluctuation driven semiclassical transport phenomenon

Sarma

Hwang

2013

Phys. Rev. B

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We theoretically consider the carrier density tuned (apparent) two-dimensional (2D) metalinsulator-transition (MIT) in semiconductor heterostructure-based 2D carrier systems as arising from a classical percolation phenomenon in the inhomogeneous density landscape created by the long-range potential fluctuations induced by random quenched charged impurities in the environment. The long-range Coulomb disorder inherent in semiconductors produces strong potential fluctuations in the 2D system where a fraction of the carriers gets trapped or classically localized, leading to a mixed 2-component semiclassical transport behavior at intermediate densities where a fraction of the carriers is mobile and another fraction immobile. At high carrier density, all the carriers are essentially mobile whereas at low carrier density all the carriers are essentially trapped since there is no possible percolating transport path through the lake-and-mountain inhomogeneous potential landscape. The low-density situation with no percolation would mimic an insulator whereas the high-density situation with allowed percolating paths through the lake-and-mountain energy landscape would mimic a metal with the system manifesting an apparent MIT in between. We calculate the transport properties as a function of carrier density, impurity density, impurity location, and temperature using a 2-component (trapped and mobile carriers) effective medium theory. Our theoretically calculated transport properties are in good qualitative agreement with the experimentally observed 2D MIT phenomenology in 2D electron and hole systems. We find a high (low) density metallic (insulating) temperature-dependence of the 2D resistivity, and an intermediate-density crossover behavior which could be identified with the experimentally observed 2D MIT. The calculated density-and temperature-dependent resistivity in our theory mimics the phenomenology of 2D MIT experiments with reasonable parameter values for the background disorder.

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Section: Introductionsupporting

confidence: 70%

Two-dimensional metal-insulator transition as a potential fluctuation driven semiclassical transport phenomenon

Sarma

Hwang

2013

Phys. Rev. B

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“…Resistance noise was also measured in very clean 2D hole systems (2DHS) in GaAs (Leturcq et al, 2003;Deville et al, 2005;Deville et al, 2006). Even though an orders of magnitude enhancement of the noise was observed with decreasing T and hole density p s , similar to the results on 2DES in Si and bulk doped Si, no evidence for strong correlations or glassiness was found.…”

Section: Discussionmentioning

confidence: 52%

Glassy Dynamics of Electrons Near the Metal–Insulator Transition

Popović¹

2012

Conductor-Insulator Quantum Phase Transitions

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PrefaceThis review first describes the evidence that strongly suggests the existence of the metal-insulator transition (MIT) in a two-dimensional electron system in Si regardless of the amount of disorder. Extensive studies of the charge dynamics demonstrate that this transition is closely related to the glassy freezing of electrons as temperature T → 0. Similarities to the behavior of three-dimensional materials raise the intriguing possibility that such correlated dynamics might be a universal feature of the MIT regardless of the dimensionality. Contents 0.1 Introduction 1 0.2 Metal-insulator transition in two dimensions 3 0.3 Glassy freezing of electrons in two dimensions 15 0.4 Summary 28 0.5 Discussion 29 0.6 Acknowledgments 33 References 34 Free energy landscape Configuration space coordinate F Glass Fig. 0.1 The free-energy (F ) landscape of a glassy system. The horizontal axis represents the one-dimensional projection of the configurational coordinates of the degrees of freedom.Metal-insulator transition in two dimensions ¿ Lee and Ramakrishnan 1985). They have an additional advantage that all the relevant parameters, carrier concentration, disorder and interactions, can be varied relatively easily. This review will describe some of the work that has demonstrated that the 2DES in Si is an excellent model system not only for studying the MIT in two dimensions (2D), but also for investigating the nearly universal nonequilibrium behavior exhibited by a large class of both three-dimensional (3D) and 2D systems (e.g. spin glasses, supercooled liquids, granular films). In fact, the work on the 2DES in Si provides additional strong evidence that many such universal features are robust manifestations of glassiness, regardless of the dimensionality of the system. The dimensionality plays an important role in the MIT. In 2D, for example, the very existence of the metal and the MIT had been questioned for many years. Recently, considerable experimental evidence has become available in favor of such a transition. Some of that work has been described in several review papers (e.g. Kravchenko and Sarachik 2004) with a focus on very clean (low-disordered) samples. This review will first extend that discussion to the cases of higher disorder in order to (a) demonstrate that the 2D MIT is observed in all 2DES in Si regardless of the amount of disorder, (b) point out important similarities to the MIT in 3D systems, and (c) set the stage for the discussion of glassy dynamics near the MIT. As summarized below, the 2DES in Si exhibits all the main manifestations of glassiness: slow, correlated dynamics; nonexponential relaxations; diverging equilibration time, as T → 0; aging and memory. The results provide strong support to theoretical proposals describing the 2D MIT as the melting of a Coulomb glass (Dobrosavljević et al.

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