Starts 4 Jun 2012 17:00
Ends 4 Jun 2012 20:00
Central European Time
ICTP
Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11 I - 34151 Trieste (Italy)
Incompressibility in the fractional QHE is identified as a variant of Mott-Hubbard incompressibility, where additional electrons are excluded from a region occupied by a “composite boson” of p electrons in q orbitals (or p electrons with q “attached flux quanta”) at Landau-level filling \nu = p/q. The new ingredient is that the shape of this “exclusion zone” is described by an intrinsic ”unimodular” (determinant = 1) spatial metric tensor field g_{ab}(x,t), that is a true dynamical variable that fluctuates about the shape that minimizes the correlation energy of the FQH state. It emerges that the electron density is pinned to the combination peB-\hbar s K_g rather than to the magnetic flux density B alone, where K_g is the gaussian curvature of the metric, and s is a new characteristic topologically-quantized ”guiding-center spin” related to the so-called ”shift” of the FQH state. This metric can be seen in the Laughlin state as a explicit variational parameter that has remained hidden for the past thirty years because of a fundamental misinterpretation of the Laughlin state as a ”lowest Landau level Schrödinger wavefunction”: (in fact it is a guiding-center coherent state that does not depend on which Landau level is partially filled).
  • M. Poropat