EVIDENCE FOR SKYRMIONS AND SINGLE SPIN FLIPS IN THE INTEGER QUANTIZEDHALL-EFFECT

We have employed tilted-field magnetotransport measurements of the ene rgy gap for the odd-integer quantized Hall states at Landau level fill ing factors nu = 1, 3, and 5 to determine the spin of thermally excite d quasielectron-quasihole pairs. At nu = 1 our data show that as many as 7 electron spin Rips accompany such excitations, while at nu = 3 an d 5 apparently only a single spin flips. These results lend support to the recent suggestions that ''Skyrmionic'' quasiparticles are the low est-lying charged excitations of the fully polarized nu = 1 quantum Ha ll fluid but are not at the higher odd-integer fillings.