Optical absorption to probe the quantum Hall ferromagnet at filling factor nu=1.
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 nu=1 and at very low temperatures ( approximately 40 mK). A small change in filling factor (deltanu approximately +/-0.01) leads to a significant depolarization. This suggests that the itinerant quantum Hall ferromagnet at nu=1 is surprisingly fragile against increasing temperature, or against small changes in filling factor.
Plochocka
P
P
Laboratoire National des Champs Magnétiques Intenses, Grenoble High Magnetic Field Laboratory, 38042 Grenoble, France. Paulina.Plochocka@grenoble.cnrs.fr
Schneider
J M
JM
Maude
D K
DK
Potemski
M
M
Rappaport
M
M
Umansky
V
V
Bar-Joseph
I
I
Groshaus
J G
JG
Gallais
Y
Y
Pinczuk
A
A