Weak antilocalization measurements on a 2‐dimensional electron gas in an InGaSb/InAlSb heterostructure

Abstract

In this article a study of the weak antilocalization effect in an InGaSb/InAlSb two-dimensional electron gas (2DEG) as a function of temperature is presented. Detailed information about the spin-splitting and transport parameters of the electronic system was obtained by fitting the model of Golub [L. E. Golub, Phys. Rev. B 71, 235310 (2005)] to the magnetoconductance data. A good agreement between the model and the experiment was achieved, taking into account only one of the k-linear spin-orbit coupling terms. Zero field spin-splitting energy was estimated to be of 1 meV.1 Introduction Recently, investigation of spin-dependent effects in the semiconductors became of great importance because of the rapid development of spin electronics. One of the major objectives is obtaining control over the spin in electronic devices. Thereupon arose an interest in semiconductor materials with pronounced spin-orbit interaction. Narrow band gap III-V compound semiconductors, in particular InSb and InSb-based ternary alloys, attracted especial interest because of the predicted strong spin-orbit interaction and furthermore because of the large effective g-factor, which is almost 100 times larger than the g-factor of GaAs [1].Magnetotransport measurements are a powerful tool for studying spin-dependent effects in semiconductors. In contrast to the analysis of the beating pattern in the Shubnikov-de Haas oscillations, the study of weak antilocalization (WAL) effect is an unambiguous indication of presence of spin-orbit interaction [2]. In this report we will focus on quantum corrections to the magnetoconductance around zero magnetic field in a two-dimensional electron gas (2DEG), based on an InGaSb/InAlSb heterostructure. We fitted the experimental data by a theoretical model and extracted characteristic scattering parameters, i.e. the phase coherence time τ φ and the spin relaxation time τ so .

Interference-induced magnetoresistance in HgTe quantum wells

“…In other words, one can use a single-band approximation with the particles described by the Green's functions (22) with self-energy Σ determined by the spinor-dressed disorder, Eq. (24).…”

“…Such a propagator obeys kinetic equation which can be derived by means of standard diagrammatic technique. The collision integral of this equation contains both ingoing and outgoing terms describing the scattering from the momentum k ′ to the momentum k. The outgoing rate is determined by the rate γ = ImΣ entering the single-particle Green's function (22). To find ingoing rate we notice that the disorder vertex lines in the Cooperon propagator are also "dressed" by the Dirac spinor factors.…”

Spin-Orbit Interaction in Symmetric Wells with Two Subbands

“…This new s-o interaction gives rise to a non-zero spin Hall conductivity, renormalizes the bulk mass by ∼ 5% (measurable via cyclotron resonance [23]) in double wells and can induce a cycloidal zitterbewegung. Weak antilocalization [20,31] should offer another possibility to measure η.…”

Spin-orbit interaction determined by antilocalization in an InSb quantum well

“…7 AL magnetotransport measurements thus form a valuable experimental tool to access SOI parameters and in semiconductor systems. [9][10][11][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] In this context, we present low-field magnetotransport measurements on an InSb two-dimensional electron system ͑2DES͒ in an InSb/ In 0.85 Al 0.15 Sb heterostructure at temperatures T Ͻ 20 K. The observed dependence of the conductivity on H is discussed in terms of AL, and enables us to determine the dominant SOI terms, and to compare our findings with the literature on n-type InSb quantum wells.…”