Quantum dot electrons as controllable scattering centers in the vicinity of a two-dimensional electron gas

Russ, Marco; Meier, Cedrik; Marquardt, B.; Lorke, Axel; Reuter, D.; Wieck, A. D.

doi:10.1080/01411590600960893

Cited by 13 publications

(6 citation statements)

References 12 publications

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“…Investigation by Russ et al on the nature of the interaction between the 2DEG and InAs quantum dots separated by a tunnel barrier revealed that the quantum dots act as uncorrelated scattering centers and enhance the scattering by strongly interacting with the 2DEG [13]. The quantum lifetime of electrons calculated from the Dingle plot for sample B was found to vary between 0.37 and 0.5 ps in the range of gate voltages studied.…”

Section: Resultsmentioning

confidence: 93%

Crossover from negative to positive magnetoresistance in the double quantum well system with different starting disorder

Kannan¹,

Karamad²,

Kim³

et al. 2010

J. Phys.: Condens. Matter

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Magnetotransport measurements were performed in two widely separated double quantum well systems with different starting disorders. In the weak magnetic field regime, a crossover from negative to positive magnetoresistance in the longitudinal resistivity was observed in the system with weak disorder when the electron densities in the neighboring wells were significantly unbalanced. The crossover was found to be the result of the exchange-energy-assisted interactions between the electrons occupying the lowest subbands in the neighboring wells. In the case of the system with strong disorder short range scattering dominated the scattering process and no such transition in longitudinal resistivity in the low magnetic field regime was observed. However, at high magnetic fields, sharp peaks were observed in the Hall resistance due to the interaction between the edge states in the quantum Hall regime.

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Section: Resultsmentioning

confidence: 93%

Crossover from negative to positive magnetoresistance in the double quantum well system with different starting disorder

Kannan¹,

Karamad²,

Kim³

et al. 2010

J. Phys.: Condens. Matter

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“…The sample growth sequence can be found in Ref. [ 11 , 12 ]. We have prepared Hall bar devices with a metallic top gate in order to control the charge state of the dots and the 2DEG.…”

Section: Sample Descriptionmentioning

confidence: 99%

“…Ref. [ 11 ]). This method makes it easily possible to rule out a defect-related signal because such a signal would not exhibit the characteristics of the QD states.…”

Section: Hysteresis Measurementsmentioning

confidence: 99%

A Two-Dimensional Electron Gas as a Sensitive Detector for Time-Resolved Tunneling Measurements on Self-Assembled Quantum Dots

et al. 2010

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A two-dimensional electron gas (2DEG) situated nearby a single layer of self-assembled quantum dots (QDs) in an inverted high electron mobility transistor (HEMT) structure is used as a detector for time-resolved tunneling measurements. We demonstrate a strong influence of charged QDs on the conductance of the 2DEG which allows us to probe the tunneling dynamics between the 2DEG and the QDs time resolved. Measurements of hysteresis curves with different sweep times and real-time conductance measurements in combination with an boxcar-like evaluation method enables us to unambiguously identify the transients as tunneling events between the s- and p-electron QD states and the 2DEG and rule out defect-related transients.

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“…The charged QDs act as Coulomb scattering centers, reducing the mobility of the 2DHG. 19,20 In addition, using Gauss' law it was predicted that the transfer of holes in QDs lead to a reduction in the carrier density in the 2DHG. [21][22][23] Both, the lowered charge carrier density and the decreased mobility reduce the conductance during the down sweep, resulting in a lower current trace compared to the up sweep.…”

mentioning

confidence: 99%

Hole-based memory operation in an InAs/GaAs quantum dot heterostructure

Marent

Nowozin

Gelze

et al. 2009

Applied Physics Letters

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We present an InAs/GaAs quantum dot ͑QD͒ memory structure with all-electrical data access which uses holes as charge carriers. Charging and discharging of the QDs are clearly controlled by a gate voltage. The stored information is read-out by a two-dimensional hole gas underneath the QD-layer. Time resolved drain-current-measurements demonstrate the memory operation. Present write times are 80 ns.

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Quantum dot electrons as controllable scattering centers in the vicinity of a two-dimensional electron gas

Cited by 13 publications

References 12 publications

Crossover from negative to positive magnetoresistance in the double quantum well system with different starting disorder

Crossover from negative to positive magnetoresistance in the double quantum well system with different starting disorder

A Two-Dimensional Electron Gas as a Sensitive Detector for Time-Resolved Tunneling Measurements on Self-Assembled Quantum Dots

Hole-based memory operation in an InAs/GaAs quantum dot heterostructure

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