Evidence for two-dimensional correlated hopping in arrays of Ge/Si quantum dots

Yakimov, A. I.; Двуреченский, А. В.; Nenashev, A. V.; Никифоров, А. И.

doi:10.1103/physrevb.68.205310

Cited by 15 publications

(7 citation statements)

References 13 publications

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“…To carefully check the scaling hypothesis, one has to provide for a sufficiently wide range of conductance values in the system. It has been shown recently 13,14 that hopping conductance, which determines the charge-transport mechanism in Ge/Si QD arrays at low temperatures ͑Շ20 K͒, broadly varies, from 4 ϫ 10 −6 to 6 ϫ 10 −12 Ohm −1 , when the filling factor of QDs with holes increases from 0.5 to 6. Moreover, not only the conductance, but also the localization radius in this system was shown 15 to be substantially dependent on , with -values varying by more than one order of magnitude as we pass from full-to half-filled QD ground state.…”

Section: Introductionmentioning

confidence: 99%

Strong to weak localization transition and two-parameter scaling in a two-dimensional quantum dot array

et al. 2009

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The transition from strong to weak localization behavior was observed in two-dimensional Ge/Si quantum dot structure under the variation in the quantum dot occupancy, their areal density and annealing of the structures at 480-625°C. To clarify the carrier transport mechanism and separate the hopping and diffusive regimes, the temperature dependence of conductance and conductance nonlinearity were analyzed in the structures with different correlations between the disorder and interaction. It was shown that the change in the relative disorder without significantly changing the interaction keeps the system inside the one-parameter scaling. The role of the interaction in two-parameter scaling was revealed by observing the shift of Gell-Mann-Low scaling function for the samples with large variation in the Coulomb interaction.

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Section: Introductionmentioning

confidence: 99%

Strong to weak localization transition and two-parameter scaling in a two-dimensional quantum dot array

et al. 2009

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“…If the QD array density is of the order of (2-4) · 10 11 cm −2 , the holes localized in QDs become tunnel-coupled and, at low temperatures (<30 K), hopping conductivity via Coulomb gap states is observed [1]. A feature of lateral hopping transport in an array of tunnel-coupled QDs is its strong and nonmonotonic dependence on the filling of QDs by charge carriers.…”

Section: Introductionmentioning

confidence: 99%

Mesoscopic structures with GE quantum dots in SI for single-photon detectors

Stepina

Valkovskii

Двуреченский

et al. 2014

Optoelectron.Instrument.Proc.

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The results of investigation of photostimulated current switching during irradiation of mesoscopic structures based on Ge quantum dots in Si by weak infrared fluxes are presented. The small dimensions of the channel (approximately 70-200 nm) provide an opportunity to observe giant photoconductivity fluctuations which are due to the strong dependence of the hopping current on the filling of quantum dots by charge carriers. Replacing the silicon substrate with silicon-on-insulator made it possible to exclude the predominance of band conduction over hopping conduction at high temperatures and increase the photodetection temperature from 4.2 to approximately 100 K. The obtained results are the basis for the creation of a single-photon detector in a wide wavelength range.

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“…Hopping conduction in this system was studied both theoretically and experimentally in [1][2][3]. Fur thermore, the magnetoresistance in an array of quan tum dots with hopping conduction was experimentally studied in [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Negative magnetoresistance in the regime of hopping conduction through p states at quantum dots

Шумилин

2012

Jetp Lett.

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The magnetoresistance in the system of quantum dots with hopping conduction and filling factor 2 < ν < 3 in the limit of small quantum dots has been considered. In this case, hopping conduction is determined by p states. It has been shown that the system exhibits negative magnetoresistance associated with a change in the wavefunctions of p states in a magnetic field. This mechanism of magnetoresistance is linear in magnetic field in a certain range of fields and can compete with the known interference mechanism of magnetoresis tance. The magnitude of this magnetoresistance is independent of the temperature at fairly low temperatures and increases with a decrease in the size of a quantum dot.

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Evidence for two-dimensional correlated hopping in arrays of Ge/Si quantum dots

Cited by 15 publications

References 13 publications

Strong to weak localization transition and two-parameter scaling in a two-dimensional quantum dot array

Strong to weak localization transition and two-parameter scaling in a two-dimensional quantum dot array

Mesoscopic structures with GE quantum dots in SI for single-photon detectors

Negative magnetoresistance in the regime of hopping conduction through p states at quantum dots

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