Université de Fribourg

Pressure-driven insulator-metal transition in cubic phase UO 2

Huang, Li ; Wang, Yilin ; Werner, Philipp

In: EPL (Europhysics Letters), 2017, vol. 119, no. 5, p. 57007

Understanding the electronic properties of actinide oxides under pressure poses a great challenge for experimental and theoretical studies. Here, we investigate the electronic structure of cubic phase uranium dioxide at different volumes using a combination of density functional theory and dynamical mean-field theory. The ab initio calculations predict an orbital-selective insulator-metal...

Université de Fribourg

Detecting phase transitions and crossovers in Hubbard models using the fidelity susceptibility

Huang, Li ; Wang, Yilin ; Wang, Lei ; Werner, Philipp

In: Physical Review B, 2016, vol. 94, no. 23, p. 235110

A generalized version of the fidelity susceptibility of single-band and multiorbital Hubbard models is systematically studied using single-site dynamical mean-field theory in combination with a hybridization expansion continuous-time quantum Monte Carlo impurity solver. We find that the fidelity susceptibility is extremely sensitive to changes in the state of the system. It can be used as a...

Université de Fribourg

Pressure-driven $4f$ localized-itinerant crossover in heavy-fermion compound ${\mathrm{CeIn}}_{3}$: A first-principles many-body perspective

Lu, Haiyan ; Huang, Li

In: Physical Review B, 2016, vol. 94, no. 7, p. 075132

The localized-itinerant nature of Ce−4f valence electrons in heavy fermion compound CeIn3 under pressure is studied thoroughly by means of the combination of density functional theory and single-site dynamical mean-field theory. The detailed evolutions of electronic structures of CeIn3, including total and partial density of states, momentum-resolved spectral functions, and valence state...

Université de Fribourg

On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime

Gukelberger, Jan ; Huang, Li ; Werner, Philipp

In: Physical Review B, 2015, vol. 91, no. 23, p. 235114

We study the two-dimensional Hubbard model in the weak-coupling regime and compare the self-energy obtained from various approximate diagrammatic schemes to the result of diagrammatic Monte Carlo simulations, which sum up all weak-coupling diagrams up to a given order. While dynamical mean-field theory provides a good approximation for the local part of the self-energy, including its frequency...

Université de Fribourg

iQIST : An open source continuous-time quantum Monte Carlo impurity solver toolkit

Huang, Li ; Wang, Yilin ; Meng, Zi Yang ; Du, Liang ; Werner, Philipp ; Dai, Xi

In: Computer Physics Communications, 2015, vol. 195, p. 140–160

Quantum impurity solvers have a broad range of applications in theoretical studies of strongly correlated electron systems. Especially, they play a key role in dynamical mean-field theory calculations of correlated lattice models and realistic materials. Therefore, the development and implementation of efficient quantum impurity solvers is an important task. In this paper, we present an open...

Université de Fribourg

Extended dynamical mean-field study of the Hubbard model with long-range interactions

Huang, Li ; Ayral, Thomas ; Biermann, Silke ; Werner, Philipp

In: Physical Review B, 2014, vol. 90, no. 19, p. 195114

Using extended dynamical mean-field theory and its combination with the GW approximation, we compute the phase diagrams and local spectral functions of the single-band extended Hubbard model on the square and simple cubic lattices, considering long-range interactions up to the third nearest neighbors. The longer-range interactions shift the boundaries between the metallic, charge-ordered...

Université de Fribourg

Electronic excitation spectra of the five-orbital Anderson impurity model: From the atomic limit to itinerant atomic magnetism

Huang, Li ; Wehling, Tim O. ; Werner, Philipp

In: Physical Review B, 2014, vol. 89, no. 24, p. 245104

We study the competition of Coulomb interaction and hybridization effects in the five-orbital Anderson impurity model by means of continuous time quantum Monte Carlo, exact diagonalization, and Hartree-Fock calculations. The dependence of the electronic excitation spectra and thermodynamic ground-state properties on the hybridization strength and the form of the Coulomb interaction is...

Université de Fribourg

Non-Fermi-liquid behavior in cubic phase BaRuO₃: A dynamical mean-field study

Huang, Li ; Ao, Bingyun

In: Physical Review B, 2013, vol. 87, no. 16, p. 165139

Motivated by the recently synthesized cubic phase BaRuO₃ under high pressure and high temperature, a thorough study has been conducted on its temperature-dependent electronic properties by using the state-of-the-art ab initio computing framework of density-functional theory combined with dynamical mean-field theory. At ambient condition the cubic phase BaRuO₃ should be a correlated Hund's...