Conductivity of a spin-polarized two-dimensional electron liquid in the ballistic regime

Abstract

In the ballistic regime, the metallic temperature dependence of the conductivity in a two-dimensional electron system in silicon is found to change nonmonotonically with the degree of spin polarization. In particular, it fades away just before the onset of complete spin polarization but reappears again in the fully spin-polarized state, being, however, suppressed relative to the zero-field case. Analysis of the degree of the suppression allows one to distinguish between the screening and the interaction-based theories.

Spin-polarization-induced tenfold magnetoresistivity of highly metallic two-dimensional holes in a narrowGaAsquantum well

“…For weak disorder, semiclassical calculations based on T-and B-dependent screening 14 showed good agreement with highly conductive Si-MOSFET's, in which a factor 3 to 4 increase in ͑B ͉͉ ͒ and a weak T dependent ͑T͒ in the spin polarized state were observed. 17,18 Refined screening models including exchange and correlation effects may produce a larger increase in ͑B ͉͉ ͒, but only when disorder is sufficiently strong and carrier density sufficiently low to be in the vicinity of the MIT. 19 Our observation of such large ͑B ͉͉ ͒ for metallic 2DHS with e 2 /h ͑or k F l 1͒ calls for further theoretical understanding of spin-dependent transport in dilute metallic 2D systems with strong correlations and weak disorder.…”

Resistance asymmetry of a two-dimensional electron gas caused by an effective spin injection

“…[2][3][4][7][8][9][10][11][12] It was shown in Refs. 7 and 8 that the metalliclike conductivity of Si-MOSFET first decreases with increase of in-plane magnetic field and then saturates to a new constant value when electrons become fully polarized.…”

Low-density spin-polarized transport in two-dimensional semiconductor structures: Temperature-dependent magnetoresistance of Si MOSFETs in an in-plane applied magnetic field

“…There is, in fact, a qualitative physical explanation 23 for the observed temperature independence of the high-field magnetoresistance in Si MOSFETs, which is generic and universal in nature and does not invoke the ad hoc explanation of the field-induced lifting of the silicon valley degeneracy we propose above as a possibility. This explanation is, however, based on a categorical repudiation of the existing experimental claims 7 that the constancy ͑i.e., temperature in-dependence͒ of ͑T ; B Ͼ B s ͒ as a function of temperature at high parallel fields does not in any way indicate a fundamental suppression of "metallicity" ͑i.e., the metallic temperature dependence͒ in the fully spin-polarized Si MOSFETs, as has been repeatedly emphasized by several experimental groups in the past.…”