Evidence for Skyrmions and single spin flips in the integer quantized Hall effect

We have employed tilted-field magnetotransport measurements of the energy gap for the odd-integer quantized Hall states at Landau level filling factors ν=1, 3, and 5 to determine the spin of thermally excited quasielectron-quasihole pairs. At ν=1 our data show that as many as 7 electron spin flips accompany such excitations, while at ν=3 and 5 apparently only a single spin flips. These results lend support to the recent suggestions that "Skyrmionic" quasiparticles are the lowest-lying charged excitations of the fully polarized ν=1 quantum Hall fluid but are not at the higher odd-integer fillings