Electron–hole doping asymmetry of Fermi surface reconstructed in a simple Mott insulator

With the hierarchical Green’s function approach, we study a doped Mott insulator described with the Hubbard model by analytically solving the equations of motion of an one-particle Green’s function and related multiple-point correlation functions, and find that the separation of the spin and charge degrees of freedom of the electrons is an intrinsic character of the doped Mott insulator. For enough of large on-site repulsive Coulomb interaction, we show that the spectral weight of the one-particle Green’s function is proportional to the hole doping concentration that is mainly produced by the charge fluctuation of electrons, while the excitation spectrum of the electrons is composed of two parts: One is contributed by the spin fluctuation of the electrons, which is proportional to the hole doping concentration, and another one is coming from the coupling between the charge and spin fluctuations of the electrons that takes the maximum at undoping. All of these low energy/temperature physical properties originate from the strong on-site Coulomb interaction. The present results are consistent with the spectroscopy observations of the cuprate superconductors and the numerical calculations in normal state above the pseudogap regime.

Download Full-text

Emergence of quasiparticles in a doped Mott insulator

Communications Physics ◽

10.1038/s42005-020-00480-5 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Yao Wang ◽

Yu He ◽

Krzysztof Wohlfeld ◽

Makoto Hashimoto ◽

Edwin W. Huang ◽

...

Keyword(s):

Hubbard Model ◽

Single Layer ◽

Mott Insulator ◽

Spectral Weight ◽

Particle Spectrum ◽

Electron Hole ◽

Strong Electron ◽

Side Band ◽

Angle Resolved Photoemission Spectroscopy ◽

Weakly Coupled

AbstractHow a Mott insulator develops into a weakly coupled metal upon doping is a central question to understanding various emergent correlated phenomena. To analyze this evolution and its connection to the high-Tc cuprates, we study the single-particle spectrum for the doped Hubbard model using cluster perturbation theory on superclusters. Starting from extremely low doping, we identify a heavily renormalized quasiparticle dispersion that immediately develops across the Fermi level, and a weakening polaronic side band at higher binding energy. The quasiparticle spectral weight roughly grows at twice the rate of doping in the low doping regime, but this rate is halved at optimal doping. In the heavily doped regime, we find both strong electron-hole asymmetry and a persistent presence of Mott spectral features. Finally, we discuss the applicability of the single-band Hubbard model to describe the evolution of nodal spectra measured by angle-resolved photoemission spectroscopy (ARPES) on the single-layer cuprate La2−xSrxCuO4 (0 ≤ x ≤ 0.15). This work benchmarks the predictive power of the Hubbard model for electronic properties of high-Tc cuprates.

Download Full-text

Electron and hole doping in the relativistic Mott insulator Sr2IrO4 : A first-principles study using band unfolding technique

Physical Review B ◽

10.1103/physrevb.94.195145 ◽

2016 ◽

Vol 94 (19) ◽

Cited By ~ 19

Author(s):

Peitao Liu ◽

Michele Reticcioli ◽

Bongjae Kim ◽

Alessandra Continenza ◽

Georg Kresse ◽

...

Keyword(s):

First Principles ◽

Mott Insulator ◽

Hole Doping ◽

First Principles Study

Download Full-text

Evidence for a vestigial nematic state in the cuprate pseudogap phase

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1821454116 ◽

2019 ◽

Vol 116 (27) ◽

pp. 13249-13254 ◽

Cited By ~ 8

Author(s):

Sourin Mukhopadhyay ◽

Rahul Sharma ◽

Chung Koo Kim ◽

Stephen D. Edkins ◽

Mohammad H. Hamidian ◽

...

Keyword(s):

Fermi Surface ◽

Energy Gap ◽

Density Wave ◽

Broken Symmetry ◽

Hole Doping ◽

Thermal Transitions ◽

Electronic Density ◽

Pseudogap Phase ◽

Nematic State ◽

Gap Opening

The CuO2 antiferromagnetic insulator is transformed by hole-doping into an exotic quantum fluid usually referred to as the pseudogap (PG) phase. Its defining characteristic is a strong suppression of the electronic density-of-states D(E) for energies |E| < Δ*, where Δ* is the PG energy. Unanticipated broken-symmetry phases have been detected by a wide variety of techniques in the PG regime, most significantly a finite-Q density-wave (DW) state and a Q = 0 nematic (NE) state. Sublattice-phase-resolved imaging of electronic structure allows the doping and energy dependence of these distinct broken-symmetry states to be visualized simultaneously. Using this approach, we show that even though their reported ordering temperatures TDW and TNE are unrelated to each other, both the DW and NE states always exhibit their maximum spectral intensity at the same energy, and using independent measurements that this is the PG energy Δ*. Moreover, no new energy-gap opening coincides with the appearance of the DW state (which should theoretically open an energy gap on the Fermi surface), while the observed PG opening coincides with the appearance of the NE state (which should theoretically be incapable of opening a Fermi-surface gap). We demonstrate how this perplexing phenomenology of thermal transitions and energy-gap opening at the breaking of two highly distinct symmetries may be understood as the natural consequence of a vestigial nematic state within the pseudogap phase of Bi2Sr2CaCu2O8.

Download Full-text