Laboratoire de Physique Théorique
Toulouse - UMR 5152

The nature of doped insulators (where electrons experience strong repulsion) is a key issue that has been debated for years : it was first suggested that fermionic dopants (fermions are particles that can not share the same quantum mechanical state) can change into bosonic particles (bosons are particles that can occupy the same quantum mechanic state) – so-called statistical transmutation. This spectacular phenomenon is made possible by the exotic nature of the parent insulator, a quantum liquid which might be viewed as a “soup” of fluctuating close-packed dimers. Such a state is shown to exhibit emergent (topological) quantum defects that can bind to dopants and change their fundamental quantum properties and statistics (fermionic or bosonic statistics). In a recent Letter, C.A. Lamas, A. Ralko, D.C. Cabra, D. Poilblanc and P. Pujol have proven the existence of a "statistical transmutation" symmetry : the system is invariant under a simultaneous transformation of the statistics of the dopants and change of the signs of all the dimer resonances. The authors combine exact analytical results with high performance numerical calculations to clarify this issue. The exact transformation developed in the letter enables to define a duality equivalence between doped quantum dimer Hamiltonians, and provides the analytic framework to analyze dynamical statistical transmutations. These results constitute a fundamental step in the understating of a broad family of new phenomena in the large community of strongly correlated electronic systems.

Reference : C. A. Lamas, A. Ralko, D. C. Cabra, D. Poilblanc, and P. Pujol, Phys. Rev. Lett. 109, 016403 (2012)