Low-temperature dephasing in disordered conductors: experimental aspects

Gershenson, M. E.

doi:10.1002/(sici)1521-3889(199911)8:7/9<559::aid-andp559>3.0.co;2-7

Cited by 29 publications

(15 citation statements)

References 41 publications

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“…In contrast to SWCNT mats [9] lowtemperature saturation of resistance in our SWCNT films was observed even at low bias voltage. In difference from the high bias region, where saturation of RT dependences is induced by decreasing of the height of contact barriers between nanotubes, saturation at low bias can be also explained by low temperature saturation of dephasing time inherent for weakly disordered systems [10]. In the intermediate temperature range (10 K -125 K) at low bias voltage R(T) dependences can be approximated by following equation inherent for thermal fluctuationinduced tunneling (FIT) model [11]:…”

Section: Resultsmentioning

confidence: 99%

Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

Ксеневич

Шуба

Paddubskaya

2014

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Electrical transport properties and magnetoresistance of single-wall carbon nanotubes (SWCNT) films were investigated within temperature range (2-300) K and in magnetic fields up to 8 T. A crossover between metallic (dR/dT > 0) and non-metallic (dR/dT < 0) temperature dependence of the resistance as well as low-temperature saturation of the resistance in high bias regime indicated on the diminishing of role of the contact barriers between individual nanotubes essential for the charge transport in SWCNT arrays. The magnetoresistance (MR) data demonstrated influence of weak localization and electron-electron interactions on charge transport properties in SWCNT films. The low-field negative MR with positive upturn was observed at low temperatures. At T > 10 K only negative MR was observed in the whole range of available magnetic fields. The negative MR can be approximated using 1D weak localization (WL) model. The low temperature positive MR is induced by contribution from electron-electron interactions.

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Section: Resultsmentioning

confidence: 99%

Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

Ксеневич

Шуба

Paddubskaya

2014

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“…(a) In three-dimensional, weakly disordered, conductors (L φ < L x , L y , L z ), electronphonon (e-ph) scattering is the sole dominant inelastic dephasing process [22][23][24], i.e. 1/τ i (T , l) ≈ 1/τ ep (T , l).…”

Section: Introductionmentioning

confidence: 99%

Recent experimental studies of electron dephasing in metal and semiconductor mesoscopic structures

Lin

Bird

2002

J. Phys.: Condens. Matter

369

417

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In this review, we discuss the results of recent experimental studies of the low-temperature electron dephasing time (τ φ) in metal and semiconductor mesoscopic structures. A major focus of this review is on the use of weak localization, and other quantum-interference-related phenomena, to determine the value of τ φ in systems of different dimensionality and with different levels of disorder. Significant attention is devoted to a discussion of three-dimensional metal films, in which dephasing is found to predominantly arise from the influence of electron-phonon (e-ph) scattering. Both the temperature and electron mean free path dependences of τ φ that result from this scattering mechanism are found to be sensitive to the microscopic quality and degree of disorder in the sample. The results of these studies are compared with the predictions of recent theories for the e-ph interaction. We conclude that, in spite of progress in the theory for this scattering mechanism, our understanding of the e-ph interaction remains incomplete. We also discuss the origins of decoherence in low-diffusivity metal films, close to the metal-insulator transition, in which evidence for a crossover of the inelastic scattering, from e-ph to 'critical' electron-electron (e-e) scattering, is observed. Electronelectron scattering is also found to be the dominant source of dephasing in experimental studies of semiconductor quantum wires, in which the effects of both large-and small-energy-transfer scattering must be taken into account. The latter, Nyquist, mechanism is the stronger effect at a few kelvins, and may be viewed as arising from fluctuations in the electromagnetic background, generated by the thermal motion of electrons. At higher temperatures, however, a crossover to inelastic e-e scattering typically occurs; and evidence for this large-energy-transfer process has been found at temperatures as high as 30 K. Electron-electron interactions are also thought to play an important role in dephasing in ballistic quantum dots, and the results of recent experiments in this area are reviewed. A common feature of experiments, in both dirty metals

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“…Lastly, we discuss the advantage of using three-, instead of lower-dimensional, mesoscopic structures for τ φ measurements. In 3D, the dominating inelastic process is the electronphonon scattering for which τ ep obeys a strong T −p (2 ≤ p ≤ 4) dependence [16,19]. Such a temperature variation is much stronger than the dominating p = 2/3 in one dimension and p = 1 in two dimensions (which are both due to electron-electron scattering [20]).…”

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confidence: 99%

“…where τ 0 φ dominates at the lowest measurement temperatures, and τ i is the relevant inelastic scattering time which is usually important at a (few) degree(s) kelvin and higher. In three dimensions, electron-phonon scattering is the predominant inelastic process while the Nyquist electron-electron scattering is negligibly small [19], i.e. 1/τ i ≈ 1/τ ep in eq.…”

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confidence: 99%

Effect of annealing on electron dephasing in three-dimensional polycrystalline metals

Lin

Zhong

2002

Europhys. Lett.

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We have studied the effect of thermal annealing on electron dephasing times τ φ in three-dimensional polycrystalline metals. Measurements are performed on as-sputtered and annealed AuPd and Sb thick films, using weak-localization method. In all samples, we find that τ φ possesses an extremely weak temperature dependence as T → 0. Our results show that the effect of annealing is non-universal, and it depends strongly on the amount of disorder quenched in the microstructures during deposition. The observed "saturation" behavior of τ φ cannot be easily explained by magnetic scattering. We suggest that the issue of saturation can be better addressed in three-dimensional, rather than lowerdimensional, structures.

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Low-temperature dephasing in disordered conductors: experimental aspects

Cited by 29 publications

References 41 publications

Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

Recent experimental studies of electron dephasing in metal and semiconductor mesoscopic structures

Effect of annealing on electron dephasing in three-dimensional polycrystalline metals

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