Novel Excitonic States in Quantum Hall Systems: Bound States of Spin Waves and a Valence Band Hole

If the Zeeman energy is small, the lowest energy excitations of a two dimensional electron gas at filling factor ν = 1 are spin waves (spin flip excitations). At ν slightly larger (smaller) than unity, reversed spin electrons (spin holes) can form bound states with K spin waves that are known as skyrmions, S− K (antiskyrmions, S K ). It is suggested in this work that a valence hole can also bind K spin waves to form an excitonic complex X K , analogous to the S K . One spin hole of the S K is simply replaced by the valence hole. At ν ≤ 1, a small number of S K ’s are present before introduction of the valence hole. The S K –X K repulsion leads to correlations and photoluminescence similar to those of a dilute electron–charged-exciton (e–X−) system at ν ≤ 1 3 . At ν ≥ 1, the S− K –X K attraction can potentially lead to different behavior.