Orbital-selective Mott phase and non-Fermi liquid in FePS${}_3$

Abstract

The layered metal phosphorous trisulfide FePS${}_3$ is reported to be a Mott insulator at ambient conditions and to undergo structural and insulator-metal phase transitions under pressure. However, the character of the resulting metallic states has not been understood clearly so far. Here, we theoretically study the phase transitions of FePS${}_3$ using first-principles methods based on density functional theory and embedded dynamical mean field theory. We find that the Mott transition in FePS${}_3$ can be orbital-selective, with $t_{2g}$ states undergoing a correlation-induced insulator-to-metal transition while $e_g$ states remain gapped. We show that this orbital-selective Mott phase, which occurs only when non-hydrostatic pressure is used, is a bad metal (or non-Fermi liquid) with large fluctuating moments due to Hund's coupling. Further application of pressure increases the crystal-field splitting and converts the system to a conventional Fermi liquid with low-spin configurations dominant. Our results show that FePS${}_3$ is a novel example of a system that realizes an orbital-selective Mott phase, allowing tuning between correlated and uncorrelated metallic properties in an accessible pressure range ($\le$ 18 GPa).

5 pages, 5 figures

References in corpus (9)

• Strong electronic correlations from Hund's coupling
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Hybridization expansion impurity solver: General formulation and application to Kondo lattice and two-orbital models
• Orbital-Selective Mott transition out of band degeneracy lifting
• High-spin to low-spin and orbital polarization transitions in multiorbital Mott systems
• Orbital-selective Mott transitions: Heavy fermions and beyond
• Block orbital-selective Mott insulators: a spin excitation analysis
• Self-Doping Induced Orbital-Selective Mott Transition in Hg2Ru2O7

Cited by in corpus (5)

• Is the orbital-selective Mott phase stable against interorbital hopping?
• Emergence of flat bands and ferromagnetic fluctuations via orbital-selective electron correlations in Mn-based kagome metal
• Low-energy interband Kondo bound states in orbital-selective Mott phases
• Orbital selective order and ${\mathbb{Z}}_3$ Potts nematicity from a non-Fermi liquid
• Many-body electronic structure, self-doped double-exchange, and Hund metallicity in 1T-CrTe2 bulk and monolayer