Extended dual description of Mott transition beyond two-dimensional space

TL;DR

This paper extends the dual description of Mott transition from 2D to 3D, revealing new phases and phenomena related to vortex line condensation and gauge theories in higher dimensions.

Contribution

It provides an explicit formalism for Mott transition in three dimensions, generalizing previous 2D dual descriptions and uncovering novel phases such as doublon metals and doubled U(1) gauge theories.

Findings

Vortex lines induce Fermi liquid instability in 3D.

Condensation in charge degrees leads to effective fermionic actions similar to slave-particle models.

Condensation in spin degrees results in doublon metals and potential unconventional superconductivity.

Abstract

Motivated by recent work of Mross and Senthil [Phys. Rev. B \textbf{84}, 165126 (2011)] which provides a dual description for Mott transition from Fermi liquid to quantum spin liquid in two space dimensions, we extend their approach to higher dimensional cases, and we provide explicit formalism in three space dimensions. Instead of the vortices driving conventional Fermi liquid into quantum spin liquid states in 2D, it is the vortex lines to lead to the instability of Fermi liquid in 3D. The extended formalism can result in rich consequences when the vortex lines condense in different degrees of freedom. For example, when the vortex lines condense in charge phase degrees of freedom, the resulting effective fermionic action is found to be equivalent to that obtained by well-studied slave-particle approaches for Hubbard and/or Anderson lattice models, which confirm the validity of the extended dual formalism in 3D. When the vortex lines condense in spin phase degrees of freedom, a doublon metal with a spin gap and an instability to the unconventional superconducting pairing can be obtained. In addition, when the vortex lines condense in both phase degrees, an exotic doubled U(1) gauge theory occurs which describes a separation of spin-opposite fermionic excitations. It is noted that the first two features have been discussed in a similar way in 2D, the last one has not been reported in the previous works. The present work is expected to be useful in understanding the Mott transition happening beyond two space dimensions.