Spin polarization in a two-dimensional electron gas in GaAs

Abstract

In this paper, positive magnetoresistance of a dilute two-dimensional electron gas in GaAs is studied in a parallel magnetic field B. It is found that the normalized resistivity curves, ρ(B)/ρ(0), merge together when we scale the field according to B/B χ , where B χ is assumed to be the field in which full spin polarization of electrons is reached. It is also shown that the crossing field, B cross , determined by the crossover of the B 2 dependence of the resistivity, becomes lower than B χ with increasing electron density, which cannot be explained in terms of filling of the upper electron subbands in the fully spin-polarized regime. The spin susceptibility, χ, is assessed by extracting the product g * m * , where g * and m * are the effective Landé factor and electron mass, respectively. The behavior of χ with increasing electron density, however, deserves further theoretical and experimental study.

Magnetoconductivity in a Disordered and Interacting 2D p-SiGe Quantum Well

“…On the other hand, if E F (B = 0) exceeds Δ/2, the upper sub-bands will be empty and become filled in the presence of a magnetic field. We have calculated the spacing between the two energy levels (up and down) Δ = E 2 − E 1 by using the formula [32] where n indicates the n th sub-band in the energy spectrum and a is the thickness of the quantum well. In our case, the thickness a = 30 nm, and we obtain E 1 = 1.11 meV and E 2 − E 1 = 3.33 meV.…”

Evolution of ferromagnetism in two-dimensional electron gas of LaTiO3/SrTiO3

“…In addition, those phenomena provide exciting opportunities for the design of all-oxide spintronics application and field-effect devices. [14][15][16][17][18][19] Among these, understanding and control of twodimensional electron gases (2DEGs) with spin-polarized carriers have attracted tremendous attention, [18][19][20][21][22][23][24][25][26][27][28][29][30] and yet remains a distinct challenge for the experimentalists.…”