Abstract
The low-lying neutral excitation spectrum of the incompressible quantum Hall fluid at ν=5/2 is investigated by inelastic light scattering. Gapped modes are observable only in a very narrow filling factor range centered at 5/2 at energies that overlap estimates from transport activation gaps. The modes are interpreted as critical points in the wave-vector dispersion of excitations that preserve spin orientation. For very small changes |δν|â ‰ 0.01 the gapped modes disappear and a continuum of low-lying excitations takes over indicating the transition from an incompressible fluid at 5/2 to a compressible state. Observations of spin wave modes indicate spin polarization of the 5/2 and 2+1/3 quantum Hall fluids.
Original language | English (US) |
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Article number | 026801 |
Journal | Physical review letters |
Volume | 110 |
Issue number | 2 |
DOIs | |
State | Published - Jan 7 2013 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy