Accueil du site > À la une > What is the true statistics of holons ?

Didier Poilblanc

par

- 7 mai 2008

The exact nature of holons, the charged spinless excitations of the (doped) celebrated RVB state, has been debated over the last two decades. In particular, their statistics (do they behave as fermions or bosons) was still controversial. Earlier work based on a variational RVB wavefunction by Read and Chakraborty (1989) suggested that hole excitations are (weakly interacting) fermions. Such a conclusion, although only justified for small enough kinetic energy, was reproduced in the context of the doped Quantum Dimer Model (QDM) introduced later on by Kivelson. Furthermore, it was argued that the holon statistics should in fact be dictated by energetics considerations and that, under some circonstancies, a holon could bind to a “vortex”, leading to a bosonic composite. "Modern" Z2 gauge theories have recently brought powerful new tools to describe such phenomena.

**Phase diagram**Phase diagram of the "non-Frobenius" doped Quantum Dimer Model studied in this work, compared to the one of the monomer-doped ("Frobenius" case) QDM studied previously in PRL 99, 127202 (2007).

Such ideas have been formulated on the basis of a microscopic model by one of us (D. P.). A "non-Frobenius" doped QDM is introduced in such a way that the original Fermi statistics of the electrons is preserved. Despites its complexity (in contrast to previously monomer-doped QDM this model suffers from the well-known "minus sign" problem) small cluster calculations have revealed a rich phase diagram : a d-wave hole-pair unconventional superconductor appears at small enough doping and a bosonic superfluid is stable at large doping. The hole kinetic energy is shown to favor binding of topological defects to the bare fermionic holons turning them into bosons, in agreement with earlier qualittive arguments based on RVB wave-functions.

Post-scriptum :

Details and references are given in the corresponding paper "Properties of holons in the Quantum Dimer Models" published in :

D. Poilblanc, Physical Review Letters 100, 157206 (2008).

Dans la même rubrique :

- Exceeding the Pauli limit
- Measuring the size of Schrödinger’s cat
- Predicting the maximum or the minimum of a random signal
- How to reproduce bacterial propulsion in a biomimetic way ?
- Dependence of DNA Persistence Length on Ionic Strength of Solutions with Monovalent and Divalent Salts
- An argentinian-french collaboration : a novel mechanism for fractional magnetization plateaus !
- An unconventional phase transition
- Entanglement-screening by nonlinear resonances
- DNA bubbles and bending : how conformational fluctuations modify its thermal denaturation
- Phase separation and flux quantization in the doped quantum dimer model on the square and triangular lattices
- Valence Bond Entanglement Entropy
- Spin gap and string order parameter in the ferromagnetic Spiral Staircase Heisenberg Ladder
- Generic mixed columnar-plaquette phases in Rokhsar-Kivelson models
- The Pairing Glue in High-Temperature Superconductors
- Effective Theory of Magnetization Plateaux in the Shastry-Sutherland Lattice
- A gauge theory picture of an exotic transition in a dimer model
- Why DNA chains are "kinked" when observed on surfaces
- Computing fidelity at magnetic quantum phase transitions
- Quantifying Quantumness and the Quest for Queens of Quantum
- Two-dimensional ranking of Wikipedia articles