Details

Autor(en) / Beteiligte

• Lupatini, M
• Knüppel, P
• Faelt, S
• Winkler, R
• Shayegan, M
• Imamoglu, A
• Wegscheider, W

Titel

Spin Reversal of a Quantum Hall Ferromagnet at a Landau Level Crossing

Ist Teil von

• Physical review letters, 2020-08, Vol.125 (6), p.1-067404, Article 067404

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2020

Quelle

APS_美国物理学会过刊

Beschreibungen/Notizen

• When Landau levels (LLs) become degenerate near the Fermi energy in the quantum Hall regime, interaction effects can drastically modify the electronic ground state. We study the quantum Hall ferromagnet formed in a two-dimensional hole gas around the LL filling factor ν = 1 in the vicinity of a LL crossing in the heave-hole valence band. Cavity spectroscopy in the strong-coupling regime allows us to optically extract the spin polarization of the two-dimensional hole gas. By analyzing this polarization as a function of hole density and magnetic field, we observe a spin flip of the ferromagnet. Furthermore, the depolarization away from ν = 1 accelerates close to the LL crossing. This is indicative of an increase in the size of skyrmion excitations as the effective Zeeman energy vanishes at the LL crossing.