Spin Excitations of a Two-Dimensional Electron Gas in the Limit of Vanishing Landé<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">g</mml:mi></mml:math>Factor

Abstract

Electrical transport measurements under hydrostatic pressure have been used to determine the enhanced spin gap at filling factor $\ensuremath{\nu}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ in the limit of vanishing Land\'e $g$ factor $(|g|\ensuremath{\le}0.1)$. The enhanced spin gap exists even when $g\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$, and the observed variation of the spin gap around $g\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ is qualitatively consistent with recent predictions that the lowest charged excitation has a nontrivial spin order (Skyrmion).