Quantum hall effect skyrmions: nuclear magnetic resonance and heat capacity experiments
(2001)
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- Authors
- Supervisors
- Bayot, Vincent
- Abstract
- (en) Of ail the new physics generated by the highly perfect two-dimensional (2D) électron Systems, the quantum Hall effects (QHEs), integer and fractional, with their richness and complexity are perhaps the most active and excit- ing. The fractional QHE is the manifestation of a new state of électron m atter - a. peculiar, uniform density incompressible liquid phase, observed a t low tem pérature (T) and in the presence of a strong magnetic fîeld (B)perpendicular to the 2D électron layers. P art of the intellectual fascination with the QHE phases stems from the challenge of finding new concepts to describe their properties.The energy levels available to an électron confined to a 2D layer in a perpendicular magnetic field are known as Landau levels. Each Landau level can accommodate many électrons; dividing the number of électrons per unit sample area bv the degeneracy of a Landau level defines the filling factor v. At a précisé value of the magnetic field (// = 1), the 2D électrons condense into a ferromagnetic QHE ground state: the electronic System is an itinérant ferromagnet with a quantized Hall resistivity. The low-energy electron-spin dynamics of this QHE ferromagnet is extremely unusual be- cause of the subtle interplay between Coulomb interaction among électrons and Zeeman coupling of electronic spins to the external B. The elemen- tary excitations are spin-textured objects, called Skyrmions, which display complex equilibrium beha.vior reflecting liquid, crystalline and glassy phases. Qualitatively novel physics arises, moreover, because these topologica.l excitations carry electrical charge and possess an effective spin larger than th a t of a single électron
- Affiliations
Citations
Melinte, S. (2001). Quantum hall effect skyrmions: nuclear magnetic resonance and heat capacity experiments. https://hdl.handle.net/2078.5/124329