Measurements on a multilayer two-dimensional electron system (2DES) near Landau-level filling ν = 1 reveal the disappearance of the nuclear spin contribution to the heat capacity as the ratio∼g between the Zeeman and Coulomb energies exceeds a critical value∼gc≈ 0.04. This disappearance suggests the vanishing of the Skyrmion-mediated coupling between the lattice and the nuclear spins as the spin excitations of the 2DES make a transition from Skyrmions to single spin flips above∼gc. Our experimental∼gcis smaller than the calculated∼gc= 0.054 for an ideal 2DES. We discuss possible origins of this discrepancy.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)