Mott Quantum Critical Points at finite doping

Abstract

Strongly correlated materials often undergo a Mott metal-insulator transition, which is tipically first-order, as a function of control parameters like pressure. Upon doping, rich phase diagrams with competing instabilities are found. Yet, the conceptual link between the interaction-driven Mott transition and the finite-doping behavior lacks a clear connection with the theory of critical phenomena. In a prototypical case of a first-order Mott transition the surface associated with the equation of state for the homogeneous system is "folded" so that in a range of parameters stable metallic and insulating phases exist and are connected by an unstable metallic branch. Here we show that tuning the chemical potential the zero-temperature equation of state gradually unfolds. Under general conditions, we find that the Mott transition evolves into a first-order transition between two metals, associated to a phase separation region ending in a quantum critical point (QCP) at finite doping. This scenario is here demonstrated solving a simple multi-orbital Hubbard model relevant for the Iron-based superconductors, but its origin - the splitting of the atomic ground state multiplet by a small energy scale, here Hund's coupling - is much more general. A strong analogy with cuprate superconductors is traced.

7 pages, 3 figures, supplementary information

References in corpus (15)

• Continuous-time Monte Carlo methods for quantum impurity models
• The numerical renormalization group method for quantum impurity systems
• Strong electronic correlations from Hund's coupling
• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Energy resolution and discretization artefacts in the numerical renormalization group
• Orbital selective Mott transition in multi-band systems: slave-spin representation and dynamical mean-field theory
• Rotationally-invariant slave-boson formalism and momentum dependence of the quasiparticle weight
• Finite doping signatures of the Mott transition in the two-dimensional Hubbard model
• Charge order at high temperature in cuprate superconductors
• Phase separation in the particle-hole asymmetric Hubbard model
• A spin-freezing perspective on cuprates
• EDIpack: A parallel exact diagonalization package for quantum impurity problems
• Phase separation in doped Mott insulators
• Charge Order and Superconductivity as Competing Brothers in Cuprate High-$T_{\mathrm{c}}$ Superconductors

Cited by in corpus (16)

• Extended regime of coexisting metallic and insulating phases in a two-orbital electronic system
• Accuracy of ghost-rotationally-invariant slave-boson theory for multiorbital Hubbard models and realistic materials
• Slave-spin mean field for broken-symmetry states: Néel antiferromagnetism and its phase separation in multi-orbital Hubbard models
• Doping the Mott insulating state of the triangular-lattice Hubbard model reveals the Sordi transition
• Thermodynamic Stability at the Two-Particle Level
• Insulator-to-metal Mott transition facilitated by lattice deformation in monolayer $\alpha$-RuCl${}_3$ on graphite
• Orbital textures and evolution of correlated insulating state in monolayer 1T phase transition metal dichalcogenides
• Spontaneous layer selective Mott phase in the bilayer Hubbard model
• Fingerprints of a charge ice state in the doped Mott insulator Nb${}_3$Cl${}_8$
• Effective enhancement of the electron-phonon coupling driven by nonperturbative electronic density fluctuations
• Transfer learning from Hermitian to non-Hermitian quantum many-body physics
• Two $T$-linear scattering rate regimes in the triangular lattice Hubbard model
• Intertwined superconductivity and orbital selectivity in a three-orbital Hubbard model for the iron pnictides
• Quantitative Determination of the Critical Points of Mott Metal-Insulator Transition in Strongly Correlated Systems
• Local magnetic moment formation and Kondo screening in the presence of Hund exchange: the two-band Hubbard model analysis
• The Frenkel line and the pseudogap: an analogy between classical and electronic fluids