Experimental study on magnetoresistance phenomena in n-type Si/SiGe quantum wires

Veen, R. G. van; Verbruggen, A. H.; Drift, E. van der; Schäffler, F.; Radelaar, S.

doi:10.1088/0268-1242/14/6/304

Cited by 10 publications

(2 citation statements)

References 33 publications

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“…Kurdak et al [272] used wet etching to fabricate quasi-ballistic wires and rings in InGaAs/InAlAs heterojunctions, and used the weak-localization magnetoresistance and Aharonov-Bohm oscillations to extract an estimate for the dephasing time. In both types of structure, evidence for saturation was found at temperatures below 0.35 K. van Veen et al [279] used reactive-ion etching to fabricate quasi-ballistic, Si/SiGe quantum wires and obtained values for the dephasing time from the weak-localization magnetoresistance. A weak temperature dependence of this parameter was found below a kelvin, suggestive of saturation.…”

Section: Dephasing In Dirty and Quasi-ballistic Quantum Wiresmentioning

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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Section: Dephasing In Dirty and Quasi-ballistic Quantum Wiresmentioning

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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“…For diffusive conducting systems at sufficiently low temperatures, these so-called universal conductance fluctuations (UCFs) have a characteristic amplitude, $e 2 =h, independent of sample size and material, and they are generally thought to be well understood. 18) Similar conductance fluctuations are also observed and discussed in mesoscopic quantum Hall (QH) systems, [19][20][21][22][23][24][25][26][27][28] quantum wires, [29][30][31][32] quantum point contacts, 33,34) open cavity (quantum dot) systems, [35][36][37][38][39][40][41][42] and loop systems. 43) Interpretations of different experiments include the modification of UCF in high field, 19,20) the tunneling between opposite edge states through bulk inhomogeneities, [22][23][24] the influences of charging effects, 25,26) and the network of compressible-incompressible regions.…”

Section: Introductionmentioning

confidence: 68%

Correlation Field Analysis of Magnetoresistance of GaN/AlGaN Heterostructure Grown on Si Substrate

Lin

Han

Chen

et al. 2008

jjap

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We analyze the conductance fluctuations for a bulk two-dimensional electron system in a GaN/Al 0:15 Ga 0:85 N heterostructure grown on a p-type Si(111) substrate, and calculate the correlation field B c with the autocorrelation function FðÁBÞ ¼ hGðB þ ÁBÞ À GðBÞi, in the temperature range 0:27 T 3 K, which is employed as a self-thermometer to obtain the effective carrier temperature T e as a function of the measurement current I. We find that the temperature dependence agrees well with simple expectations for universal conductance fluctuations in metals, while the observed amplitude is reduced. In the study of hot-carrier phenomena, we also obtain T e $ I 0:5 , which agrees with some theoretical prediction.

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Electronic properties of Si/SiGe ultrathin quantum wire superlattices

Benkhettou¹,

Rached²,

Sekkal

2003

Physica Status Solidi (b)

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The electronic bandstructure of ultrathin Si/Si 1Àx Ge x quantum wire superlattices is investigated using two methods. The first is the pseudopotential method of M. Jaros. The second is the first-principles method of full potential linear muffin-tin orbitals (FP-LMTO) coupled to a plane-wave basis (PLW) in the interstitial regions, which is employed to verify the results obtained with the previous method. Larger quantum wire superlattices (but always ultrathin) are also investigated. The most important result is that one of these systems is found to be promising for optoelectronic applications.

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Experimental study on magnetoresistance phenomena in n-type Si/SiGe quantum wires

Cited by 10 publications

References 33 publications

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

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

Correlation Field Analysis of Magnetoresistance of GaN/AlGaN Heterostructure Grown on Si Substrate

Electronic properties of Si/SiGe ultrathin quantum wire superlattices

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