Kukushkin IV, Smet JH, Eberl K
Max-Planck-Institut fur Festkorperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany and Institute of Solid State Physics, RAS, Chernogolovka, 142432 Russia.
Phys Rev Lett. 2000 Oct 23;85(17):3688-91. doi: 10.1103/PhysRevLett.85.3688.
We demonstrate that the temperature dependence of the electron spin polarization for the fractional states nu = 1/3 and nu = 2/3 displays activated behavior. This study enables the first measurement of the fractional quantum Hall spin-flip gaps. They are found to be systematically larger in comparison with the gaps simultaneously measured in transport. For nu = 1/3 and nu = 1/2, these spin-flip gaps allow the determination of the composite fermion interaction energy. This energy is investigated as a function of the finite width of the 2D channel.
