title: Orbital-selective Mott phases of a one-dimensional three-orbital Hubbard model studied using computational techniques.
abstract: A recently introduced one-dimensional three-orbital Hubbard model displays orbital-selective Mott phases with exotic spin arrangements such as spin block states [J. Rincón et al., Phys. Rev. Lett. 112, 106405 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.106405]. In this publication we show that the constrained-path quantum Monte Carlo (CPQMC) technique can accurately reproduce the phase diagram of this multiorbital one-dimensional model, paving the way to future CPQMC studies in systems with more challenging geometries, such as ladders and planes. The success of this approach relies on using the Hartree-Fock technique to prepare the trial states needed in CPQMC. We also study a simplified version of the model where the pair-hopping term is neglected and the Hund coupling is restricted to its Ising component. The corresponding phase diagrams are shown to be only mildly affected by the absence of these technically difficult-to-implement terms. This is confirmed by additional density matrix renormalization group and determinant quantum Monte Carlo calculations carried out for the same simplified model, with the latter displaying only mild fermion sign problems. We conclude that these methods are able to capture quantitatively the rich physics of the several orbital-selective Mott phases (OSMP) displayed by this model, thus enabling computational studies of the OSMP regime in higher dimensions, beyond static or dynamic mean-field approximations.
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.|Department of Physics, Beijing Normal University, Beijing 100875, China.
authors.forename: Guangkun
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Kaushal
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Shaozhi
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Bishop
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Johnston
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.|Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alvarez
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Moreo
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Elbio
authors.initials: E
authors.lastname: Dagotto