Realization of In0.75Ga0.25As two-dimensional electron gas bilayer system for spintronics devices based on Rashba spin-orbit interaction
2012 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 112, no 11, 113711- p.Article in journal (Refereed) Published
Narrow gap InGaAs two-dimensional electron gas (2DEG) bilayer samples are fabricated and confirmed to have good electronic qualities as well as strong Rashba-type spin-orbit interactions (SOIs). The 2DEG systems are realized by molecular beam epitaxy in the form of wide quantum wells (QWs) with thicknesses tQW∼40-120nm modulation doped in both the upper and lower InAlAs barriers. From the Hall measurements, the overall mobility values of μe ∼15 m2/V s are found for the total sheet electron density of ns ∼8 × 1011/cm2, although the ns is distributed asymmetrically as about 1:3 in the upper and lower 2DEGs, respectively. Careful low temperature magneto-resistance analysis gives large SO coupling constants of α ∼20 × 10 -12eV m as well as expected electron effective masses of m*/m0 ∼0.033-0.042 for each bilayer 2DEG spin sub-band. Moreover, the enhancement of α with decrease of tQW is found. The corresponding self-consistent calculation, which suggests the interaction between the bilayer 2DEGs, is carried out and the origin of α enhancement is discussed.
Place, publisher, year, edition, pages
2012. Vol. 112, no 11, 113711- p.
Bi-layer, Bilayer systems, Coupling constants, Electron effective mass, Electronic quality, Hall measurements, InAlAs, Low temperatures, Mobility value, Modulation-doped, Narrow gap, Rashba spin orbit interaction, Rashba-type spin-orbit, Self-consistent calculation, Sheet electron density, Spintronics device, Subbands, Two-dimensional electron gas (2DEG), Hall mobility, Molecular beam epitaxy, Semiconductor quantum wells, Two dimensional, Electron gas
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-116177DOI: 10.1063/1.4766749ISI: 000312490700052ScopusID: 2-s2.0-84871196765OAI: oai:DiVA.org:kth-116177DiVA: diva2:589408
QC 201301182013-01-182013-01-162013-01-25Bibliographically approved