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.
| Original language | English |
|---|---|
| Article number | 063313 |
| Journal | Physical Review E - Statistical, Nonlinear, and Soft Matter Physics |
| Volume | 93 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 24 2016 |
Funding
G.L. thanks Shuhua Liang, Julin Rincn, and Qinlong Luo for insightful discussions. G.L., N.K., C.B., A.M., and E.D. were supported by the National Science Foundation (NSF) under Grant No. DMR-1404375. G.L. was also supported by the China Scholarship Council. G.L., N.K., and C.B. were also partially supported by the U.S. Department of Energy (DOE), Office of Basic Energy Science (BES), Materials Science and Engineering Division. G.A. was supported by the Center for Nanophase Materials Sciences, sponsored by DOE, and the DOE early career research program. Y.W., S.L., and S.J. were supported by the University of Tennessee's Science Alliance Joint Directed Research and Development (JDRD) program, a collaboration with Oak Ridge National Laboratory. The DQMC calculations used computational resources supported by the University of Tennessee and Oak Ridge National Laboratory's Joint Institute for Computational Sciences and resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility.