Metal-Insulator and Magnetic Phase Diagram of Ca${}_2$RuO${}_4$ from Auxiliary Field Quantum Monte Carlo and Dynamical Mean Field Theory

Abstract

Layered perovskite ruthenium oxides exhibit a striking series of metal-insulator and magnetic-nonmagnetic phase transitions easily tuned by temperature, pressure, epitaxy, and nonlinear drive. In this work, we combine results from two complementary state of the art many-body methods, Auxiliary Field Quantum Monte Carlo and Dynamical Mean Field Theory, to determine the low-temperature phase diagram of Ca${}_2$RuO${}_4$. Both methods predict a low temperature, pressure-driven metal-insulator transition accompanied by a ferromagnetic-antiferromagnetic transition. The properties of the ferromagnetic state vary non-monotonically with pressure and are dominated by the ruthenium $d_{xy}$ orbital, while the properties of the antiferromagnetic state are dominated by the $d_{xz}$ and $d_{yz}$ orbitals. Differences of detail in the predictions of the two methods are analyzed. This work is theoretically important as it presents the first application of the Auxiliary Field Quantum Monte Carlo method to an orbitally-degenerate system with both Mott and Hunds physics, and provides an important comparison of the Dynamical Mean Field and Auxiliary Field Quantum Monte Carlo methods.

arXiv comment6 pages, 4 figures

References in corpus (25)

• Maximally-localized generalized Wannier functions for composite energy bands
• Maximally-localized Wannier functions for entangled energy bands
• Strong electronic correlations from Hund's coupling
• Stripe order in the underdoped region of the two-dimensional Hubbard model
• TRIQS: A Toolbox for Research on Interacting Quantum Systems
• Solutions of the Two Dimensional Hubbard Model: Benchmarks and Results from a Wide Range of Numerical Algorithms
• A Constrained Path Monte Carlo Method for Fermion Ground States
• TRIQS/CTHYB: A Continuous-Time Quantum Monte Carlo Hybridization Expansion Solver for Quantum Impurity Problems
• The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4
• Structural and magnetic aspects of the metal insulator transition in Ca${}_{2-x}$Sr${}_x$RuO${}_4$
• Towards the solution of the many-electron problem in real materials: equation of state of the hydrogen chain with state-of-the-art many-body methods
• Destruction of the Mott Insulating Ground State of Ca_2RuO_4 by a Structural Transition
• Nature of the Mott transition in Ca2RuO4
• From Mott insulator to ferromagnetic metal: a pressure study of Ca${}_2$RuO${}_4$
• Electronic correlations, magnetism and Hund's rule coupling in the ruthenium perovskites SrRuO${}_3$ and CaRuO${}_3$
• Hallmarks of Hund's coupling in the Mott insulator Ca${}_2$RuO${}_4$
• Subband filling and Mott transition in Ca_{2-x}Sr_xRuO_4
• High pressure diffraction studies on Ca2RuO4
• Coupling quantum Monte Carlo and independent-particle calculations: self-consistent constraint for the sign problem based on density or density matrix
• Lattice Energetics and Correlation-Driven Metal-Insulator Transitions: The Case of Ca${}_2$RuO${}_4$
• Current-induced giant diamagnetism in the Mott insulator Ca2RuO4
• Multiorbital Quantum Impurity Solver for General Interactions and Hybridizations
• Ferromagnetism and correlation strength in cubic barium ruthenate in comparison to strontium and calcium ruthenate: a dynamical mean field study
• Theory of ferromagnetism in vanadium-oxide based perovskites
• Auxiliary Field Quantum Monte Carlo for Multiband Hubbard Models: Controlling the Sign and Phase Problems to Capture Hund's Physics

Cited by in corpus (5)

• Some Recent Developments in Auxiliary-Field Quantum Monte Carlo for Real Materials
• Picosecond volume expansion drives a later-time insulator-metal transition in a nano-textured Mott Insulator
• Decomposing imaginary time Feynman diagrams using separable basis functions: Anderson impurity model strong coupling expansion
• Fully {\it ab-initio} electronic structure of Ca${}_2$RuO${}_4$
• Accelerating ground-state auxiliary-field quantum Monte Carlo simulations by delayed update and block force-bias update