Transport effects in remote-doped InSb/AlxIn1-xSb heterostructures

Pooley, O. J.; Gilbertson, A. M.; Buckle, Philip Derek; Hall, R. S.; Buckle, L.; Emeny, M. T.; Fearn, M.; Cohen, L. F.; Ashley, T.

doi:10.1088/1367-2630/12/5/053022

Cited by 22 publications

(23 citation statements)

References 12 publications

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“…shows the opposite dependence with overall lower values of  p which we attribute to the increased screening of ionized impurities in the QW with increasing n [28]. The temperature dependence of the spin lifetimes are shown in Fig.…”

Section: Resultsmentioning

confidence: 84%

Experimental determination of the Rashba coefficient in InSb/InAlSb quantum wells at zero magnetic field and elevated temperatures

Leontiadou¹,

Litvinenko²,

Gilbertson³

et al. 2011

J. Phys.: Condens. Matter

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Abstract.We report the optical measurement of the spin dynamics at elevated temperatures and in zero magnetic field, for two types of degenerately doped n-InSb quantum wells (QWs), one asymmetric (sample A) and one symmetric (sample B) with regards to the electrostatic potential across the QW. Making use of three directly determined experimental parameters: the spin lifetime, τ s , the sheet carrier concentration, n, and the electron mobility, , we directly extract the zero field spin splitting. For the asymmetric sample where the Rashba interaction is the dominant source of spin splitting, we deduce a room temperature Rashba parameter of  = 0.09 ± 0.1 eVÅ which is in good agreement with calculations and we estimate the Rashba coefficient α 0 (a figure of merit for the ease with which electron spins can be modulated via an electric field). We review the merits/limitations of this approach and the implications of our finding for spintronic devices.

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Section: Resultsmentioning

confidence: 84%

Experimental determination of the Rashba coefficient in InSb/InAlSb quantum wells at zero magnetic field and elevated temperatures

Leontiadou¹,

Litvinenko²,

Gilbertson³

et al. 2011

J. Phys.: Condens. Matter

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“…In this way, subsequent growth of InSb QWs with high mobilities is achieved with remote delta doping (in the range 10-40 m 2 /Vs at 2 K and 4-6 m 2 /Vs at 300 K). 8,9,21,22 Here, we study the electronic properties of two sets of modulation doped InSb/Al x In 1-x Sb QW heterostructures grown by molecular beam epitaxy onto semi-insulating GaAs undoped spacer layer. The two MBL samples differ from each other only in top cap thickness and Te-doping density (fixed spacer thickness) with MBL-2 having a thinner top cap with a nominally higher doping density than MBL-1.…”

Section: Methodsmentioning

confidence: 99%

“…However, dependent on the doping density of the δ-doped region, the Al 0.2 In 0.8 Sb top cap layer can be occupied and even degenerate, presenting a low-mobility conducting channel in parallel to the high-mobility InSb 2DEG. 21 At elevated temperatures, both layers can conduct, owing to thermal excitation of carriers.…”

Section: A Multi-carrier Modelmentioning

confidence: 99%

“…Calculations of the mobility in a set of equivalent InSb/AlInSb QWs were recently performed by Orr et al 42 and Pooley et al 21 In wide 30-nm InSb QWs, typical mobilities are in the range 20-40 m 2 /Vs at 2 K and found to be limited by scattering from ionized impurities in the remote δ-doped layer. 21,42 For narrow 15-nm InSb QWs, mobilities are typically lower (7-11 m 2 /Vs at 2 K), and it was found that interface roughness scattering adds a significant contribution to the total scattering rate. 42 It follows that interface roughness scattering may also play a role in our samples.…”

Section: A Low-temperature Transportmentioning

confidence: 99%

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Suppression of the parasitic buffer layer conductance in InSb/AlxIn1−xSb heterostructures using a wide-band-gap barrier layer

et al. 2011

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InSb/Al x In 1-x Sb heterostructures display intrinsic parallel conduction in the buffer layer at room temperature that limits exploitation of the high-mobility two-dimensional electron gas (2DEG), particularly for nanostructured devices where deep isolation etch processing is impractical. Here, we demonstrate a strategy to reduce the parasitic conduction by the insertion of a pseudomorphic barrier layer of wide-band-gap alloy below the QW. We have studied the high-field magnetotransport in two types of InSb/Al x In 1-x Sb modulation doped quantum well heterostructures with and without the barrier layer in the temperature range 2-290 K and magnetic fields to 7.5 T. The conduction in the doping layer, the 2DEG, and the buffer layer are analyzed using a multi-carrier model that successfully captures the field dependence of the Hall resistance over the experimental field range. Samples with the barrier layer show significantly reduced buffer layer conduction compared to samples without. Our results are expected to be of importance for ambient temperature nano-electronic operation.

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“…4 This novel material is the subject of numerous experimental studies of transport, optical, magneto-optical, and spin-related phenomena. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] The characteristics driving the interest in this novel narrow gap material are the high carrier mobility, small effective masses, large Landé g * factor, possibility of the mesoscopic spindependent ballistic transport, and a strong spin-orbit coupling. The latter gives rise to a number of optoelectronic effects such as, e.g., terahertz photoconductivity 15 and the circular photogalvanic effect [16][17][18][19][20][21][22] recently observed in InSb QWs.…”

Section: Introductionmentioning

confidence: 99%

Interplay of spin and orbital magnetogyrotropic photogalvanic effects in InSb/(Al,In)Sb quantum well structures

et al. 2012

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We report on the observation of linear and circular magnetogyrotropic photogalvanic effects in InSb/(Al,In)Sb quantum well structures. We show that intraband (Drude-type) absorption of terahertz radiation in the heterostructures causes a dc electric current in the presence of an in-plane magnetic field. The photocurrent behavior upon variation of the magnetic field strength, temperature, and wavelength is studied. We show that at moderate magnetic fields, the photocurrent exhibits a typical linear field dependence. At high magnetic fields, however, it becomes nonlinear and inverses its sign. The experimental results are analyzed in terms of the microscopic models based on asymmetric relaxation of carriers in the momentum space. We demonstrate that the observed nonlinearity of the photocurrent is caused by the large Zeeman spin splitting in InSb/(Al,In)Sb structures and an interplay of the spin-related and spin-independent roots of the magnetogyrotropic photogalvanic effect.

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Transport effects in remote-doped InSb/Al_xIn_1-xSb heterostructures

Cited by 22 publications

References 12 publications

Experimental determination of the Rashba coefficient in InSb/InAlSb quantum wells at zero magnetic field and elevated temperatures

Experimental determination of the Rashba coefficient in InSb/InAlSb quantum wells at zero magnetic field and elevated temperatures

Suppression of the parasitic buffer layer conductance in InSb/AlxIn1−xSb heterostructures using a wide-band-gap barrier layer

Interplay of spin and orbital magnetogyrotropic photogalvanic effects in InSb/(Al,In)Sb quantum well structures

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