Observation of skyrmions in a two-dimensional hole system

Townsley, C.; Chughtai, R.; Nicholas, R.J.; Henini, M.

doi:10.1103/physrevb.71.073303

Cited by 3 publications

(4 citation statements)

References 18 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a single-particle picture, A and S are equal to 1 [7]. However, it has been shown in previous studies that in GaAs 2DEGs and 2DHGs, S and A are larger than 1 near ν ¼ 1 [7][8][9][10]12,13]. Their values depend on the ratio E Z =E C , where E Z promotes single-spin excitations reducing the skyrmion size and therefore S and A.…”

mentioning

confidence: 90%

“…In these studies, the relevance of Skyrmionic excitations in the vicinity of ν = 1 was discussed in order to explain the fast depolarization of the system away from ν = 1. It was also pointed out that, both in GaAs 2DEGs and two-dimensional hole gases (2DHGs), Skyrmions are the lowest-lying charged excitations in the vicinity of ν = 1 [1,7,9,[11][12][13]. Skyrmionic excitations rely on the interplay between Zeeman energy E Z and the Coulomb energy E C .…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2020

View full text Add to dashboard Cite

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 ¼ 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 ¼ 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.

show abstract

mentioning

confidence: 90%

mentioning

confidence: 99%

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

et al. 2020

View full text Add to dashboard Cite

show abstract

“…These are characterized by local ferromagnetic correlations while being in an overall spin-singlet state [3][4][5][6][7][8][9][10]. The QH ferromagnet and its skyrmion excitations were observed in solid state experiments [11][12][13][14][15][16][17] and attracted considerable attention recently in the context of twisted bilayer graphene [18][19][20][21] and related synthetic bilayer systems [22]. However, such experiments mainly use transport and spectroscopic measurements and therefore do not provide microscopic insights.…”

Section: Introductionmentioning

confidence: 99%

Ferromagnetism and skyrmions in the Hofstadter–Fermi–Hubbard model

et al. 2023

View full text Add to dashboard Cite

Strongly interacting fermionic systems host a variety of interesting quantum many-body states with exotic excitations. For instance, the interplay of strong interactions and the Pauli exclusion principle can lead to Stoner ferromagnetism, but the fate of this state remains unclear when kinetic terms are added. While in many lattice models the fermions' dispersion results in delocalization and destabilization of the ferromagnet, flat bands can restore strong interaction effects and ferromagnetic correlations. To reveal this interplay, here we propose to study the Hofstadter-Fermi-Hubbard model using ultracold atoms. We demonstrate, by performing large-scale DMRG simulations, that this model exhibits a lattice analog of the quantum Hall ferromagnet at magnetic filling factor ν=1. We reveal the nature of the low energy spin-singlet states around ν≈1 and find that they host quasi-particles and quasi-holes exhibiting spin-spin correlations reminiscent of skyrmions. Finally, we predict the breakdown of flat-band ferromagnetism at large fields. Our work paves the way towards experimental studies of lattice quantum Hall ferromagnetism, including prospects to study many-body states of interacting skyrmions and explore the relation to high-Tc superconductivity.

show abstract

“…9͒ and interband absorption or reflectance experiments. 11,13 In our studies we used polarization-resolved PLE ͑polarized emission intensity at a fixed energy 0 recorded as a function of excitation energy Ͼ 0 ͒, which is an indirect measure of the absorption of circularly polarized light ͑ ± ͒. Simple spin and polarization selection rules ͓cf.…”

mentioning

confidence: 99%

Quantum Hall skyrmions in a hole gas with a large spin gap

2006

View full text Add to dashboard Cite

Photoluminescence excitation spectra of a two-dimensional valence hole gas with large spin gap and strong disorder are studied in high magnetic fields. The characteristic field dependence of polarized emission associated with transitions from the lowest hole Landau level ͑LL͒ is the signature of quantum Hall ferromagnetism and small skyrmions around the LL filling factor = 1. This interpretation is supported by realistic numerical calculations of the skyrmion binding energy.

show abstract

Observation of skyrmions in a two-dimensional hole system

Cited by 3 publications

References 18 publications

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

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

Ferromagnetism and skyrmions in the Hofstadter–Fermi–Hubbard model

Quantum Hall skyrmions in a hole gas with a large spin gap

Contact Info

Product

Resources

About