Optical absorption to probe the quantum Hall ferromagnet at filling factor $ν=1$

P. Plochocka; J. M. Schneider; D. K. Maude; M. Potemski; M. Rappaport; V. Umansky; I. Bar-Joseph; J. G. Groshaus; Y. Gallais; A. Pinczuk

doi:10.1103/physrevlett.102.126806

arXiv · 0901.3959

Optical absorption to probe the quantum Hall ferromagnet at filling factor $ν=1$

P. Plochocka·J. M. Schneider·D. K. Maude·M. Potemski·M. Rappaport·V. Umansky·I. Bar-Joseph·J. G. Groshaus·Y. Gallais·A. Pinczuk

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Abstract

Optical absorption measurements are used to probe the spin polarization in the integer and fractional quantum Hall effect regimes. The system is fully spin polarized only at filling factor $ν=1$ and at very low temperatures($\sim40$ mK). A small change in filling factor ($δν\approx\pm0.01$) leads to a significant depolarization. This suggests that the itinerant quantum Hall ferromagnet at $ν=1$ is surprisingly fragile against increasing temperature, or against small changes in filling factor.

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P. Plochocka, J. M. Schneider, D. K. Maude, M. Potemski, M. Rappaport, V. Umansky, I. Bar-Joseph, J. G. Groshaus, Y. Gallais, A. Pinczuk. 2009-03-25. Optical absorption to probe the quantum Hall ferromagnet at filling factor $ν=1$. https://doi.org/10.1103/physrevlett.102.126806

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