2020/02/29 by M. Lupatini, Patrick Knüppel, P. Knüppel +7
Physics and Astronomy · #Condensed matter physics #Degenerate energy levels #Electron #Energy level splitting #Fermi energy #Ground state #Landau quantization #Magnetic field #Physics #Quantum Hall effect #Quantum and electron transport phenomena #Quantum mechanics #Quantum spin Hall effect #Semiconductor Quantum Structures and Devices #Spin polarization #Topological Materials and Phenomena #Zeeman effect #Zeeman energy #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.125.067404
published as Phys. Rev. Lett. 125, 067404 (2020)
arxiv created 2020/05/18 · openalex publication_date 2020/08/07 · arxiv updated 2020/08/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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.