Ground state of doped cuprates from first-principles quantum Monte Carlo calculations

Abstract

The author reports on new high-fidelity simulations of charge carriers in the high-Tc cuprate materials using quantum Monte Carlo techniques applied to the first principles Hamiltonian. With this high accuracy technique, the doped ground state is found to be a spin polaron, in which charge is localized through a strong interaction with the spin. This spin polaron has calculated properties largely similar to the phenomenology of the cuprates, and may be the object which forms the Fermi surface and charge inhomogeneity in these materials. The spin polaron has some unique features that should be visible in X-ray, EELS, and neutron experiments.

Incommensurate Phonon Anomaly and the Nature of Charge Density Waves in Cuprates

“…Instead, real space pictures are likely more important. These include those based on the competition between minimizing the number of broken magnetic bonds and kinetic energy and Coulomb repulsion between the doped holes [14,15,[55][56][57][58]. In such scenarios the ordering wavevector arises from a balance between different ordering tendencies and is not a crucial defining parameter of the mechanism.…”

Phase stability of TiO2polymorphs from diffusion Quantum Monte Carlo

“…[30-32, 34, 37]. This quality of wave function is sufficient to reproduce phase transitions in FeO [32], the metal-insulator transition in VO 2 [30], magnetic properties of cuprates [33,34], the phase diagram of MnO [31], the properties of ZnSe and ZnO [36,37], and group IIA and IIIB binary oxides [28]. We therefore expect this quality of wave function to be sufficient for the study of TiO 2 .…”

“…FN-DMC has been successfully applied to a wide range of molecules [26] and solids [25,27,28]. Studies of transition metal oxides using the FN-DMC method, including Ti 4 O 7 [29], VO 2 [30], MnO [31], FeO [32], Cuprates [33,34], NiO [35], ZnO [36,37], have demonstrated its outstanding capability of characterizing strong electron correlation in solids. Recent works have also demonstrated the accuracy of FN-DMC when dealing with systems dominated by dispersion interactions [38][39][40].…”

Discovering correlated fermions using quantum Monte Carlo

“…One important reason to seek out quantum Monte Carlo is for higher accuracy and fidelity to the real system without the need for adjustable parameters. For example, the metal-insulator transition in VO 2 [41] 2001 MnO Mott insulator [42] 2004 FeO phase transition [35] 2008 Undoped cuprates [43,44] 2014 Doped cuprates [45] 2015 Cerium [46] 2015 VO 2 metal-insulator [47] 2015 Defects in ZnO [48] 2015 MnO phase stability [49] 2015 ZnO/ZnSe gaps [50] 2015 NiO [51] 2015…”