Low-energy electronic spin excitations between filling factors nu=1 and 1/2 studies by optically detected nuclear magnetic resonance

Journal article

We report measurements of the spin relaxation time (Tln) for nuclei in the potential well confining a high-mobility two-dimensional electron system at a single GaAs-GaAlAs heterojunction. At low temperatures nuclear spin relaxation is dominated by electron-nuclear spin scattering: we find that Tln displays sharp maxima at incompressible states throughout the v = 2/3 hierarchy of the fractional quantum Hall effect. This behaviour is consistent with the existence of low-energy spin excitations only where the electron system is compressible. Our measurements also provide evidence for a gap in the spin excitation spectrum at ν = 1/2 .

Authors: Brockbank, R; Davies, H; Ryan, J; Thomson, M; Turberfield, A

• Publication status: Published
• Publisher: Elsevier
• Journal: PHYSICA E
• Volume: 6
• Issue: 1-4
• Pages: 56-59
• Publication date: 2000-02-01
• DOI: 10.1016/S1386-9477(99)00091-0
• ISSN: 1386-9477
• Language: English
• Keywords: fractional quantum Hall effect; NMR; Skyrmion