Abstract
We calculate the spin-drag transresistivity in a two-dimensional electron gas at temperature T in the random-phase approximation. In the low-temperature regime we show that, at variance with the three-dimensional low-temperature result the spin transresistivity of a two-dimensional spin unpolarized electron gas has the form In the spin-polarized case the familiar form is recovered, but the constant of proportionality, A, diverges logarithmically as the spin-polarization tends to zero. In the high-temperature regime we obtain (where is the effective Rydberg energy) independent of the density. Again, this differs from the three-dimensional result, which has a logarithmic dependence on the density. Two important differences between the spin-drag transresistivity and the ordinary Coulomb-drag transresistivity are pointed out. (i) The singularity at low temperature is smaller, in the Coulomb-drag case, by a factor where is the Fermi wave vector and d is the separation between the layers. (ii) The collective mode contribution to the spin-drag transresistivity is negligible at all temperatures. Moreover, the spin-drag effect is, for comparable parameters, larger than the ordinary Coulomb-drag effect.
- Received 16 December 2001
DOI:https://doi.org/10.1103/PhysRevB.68.045307
©2003 American Physical Society