Quantum critical point revisited by dynamical meanfield theory
Abstract
Dynamical meanfield theory is used to study the quantum critical point (QCP) in the doped Hubbard model on a square lattice. We characterize the QCP by a universal scaling form of the selfenergy and a spin density wave instability at an incommensurate wave vector. The scaling form unifies the lowenergy kink and the highenergy waterfall feature in the spectral function, while the spin dynamics includes both the critical incommensurate and highenergy antiferromagnetic paramagnons. Here, we use the frequencydependent fourpoint correlation function of spin operators to calculate the momentumdependent correction to the electron selfenergy. Furthermore, by comparing with the calculations based on the spinfermion model, our results indicate the frequency dependence of the quasiparticleparamagnon vertices is an important factor to capture the momentum dependence in quasiparticle scattering.
 Authors:
 Brookhaven National Lab. (BNL), Upton, NY (United States). Division of Condensed Matter Physics and Material Science
 Brookhaven National Lab. (BNL), Upton, NY (United States). Division of Condensed Matter Physics and Material Science; Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
 Publication Date:
 Research Org.:
 Brookhaven National Laboratory (BNL), Upton, NY (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 OSTI Identifier:
 1372440
 Alternate Identifier(s):
 OSTI ID: 1349541
 Report Number(s):
 BNL1139752017JA
Journal ID: ISSN 24699950; PRBMDO; R&D Project: PO015; KC0202030; TRN: US1702668
 Grant/Contract Number:
 SC00112704; FOA0001276
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Physical Review B
 Additional Journal Information:
 Journal Volume: 95; Journal Issue: 12; Journal ID: ISSN 24699950
 Publisher:
 American Physical Society (APS)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
Citation Formats
Xu, Wenhu, Kotliar, Gabriel, and Tsvelik, Alexei M. Quantum critical point revisited by dynamical meanfield theory. United States: N. p., 2017.
Web. doi:10.1103/PhysRevB.95.121113.
Xu, Wenhu, Kotliar, Gabriel, & Tsvelik, Alexei M. Quantum critical point revisited by dynamical meanfield theory. United States. doi:10.1103/PhysRevB.95.121113.
Xu, Wenhu, Kotliar, Gabriel, and Tsvelik, Alexei M. Fri .
"Quantum critical point revisited by dynamical meanfield theory". United States.
doi:10.1103/PhysRevB.95.121113. https://www.osti.gov/servlets/purl/1372440.
@article{osti_1372440,
title = {Quantum critical point revisited by dynamical meanfield theory},
author = {Xu, Wenhu and Kotliar, Gabriel and Tsvelik, Alexei M.},
abstractNote = {Dynamical meanfield theory is used to study the quantum critical point (QCP) in the doped Hubbard model on a square lattice. We characterize the QCP by a universal scaling form of the selfenergy and a spin density wave instability at an incommensurate wave vector. The scaling form unifies the lowenergy kink and the highenergy waterfall feature in the spectral function, while the spin dynamics includes both the critical incommensurate and highenergy antiferromagnetic paramagnons. Here, we use the frequencydependent fourpoint correlation function of spin operators to calculate the momentumdependent correction to the electron selfenergy. Furthermore, by comparing with the calculations based on the spinfermion model, our results indicate the frequency dependence of the quasiparticleparamagnon vertices is an important factor to capture the momentum dependence in quasiparticle scattering.},
doi = {10.1103/PhysRevB.95.121113},
journal = {Physical Review B},
number = 12,
volume = 95,
place = {United States},
year = {Fri Mar 31 00:00:00 EDT 2017},
month = {Fri Mar 31 00:00:00 EDT 2017}
}

Functional renormalizationgroup approaches, oneparticle (irreducible) reducible with respect to local Green’s functions, with dynamical meanfield theory as a starting point
We consider formulations of the functional renormalizationgroup (fRG) flow for correlated electronic systems with the dynamical meanfield theory as a starting point. We classify the corresponding renormalizationgroup schemes into those neglecting oneparticle irreducible sixpoint vertices (with respect to the local Green’s functions) and neglecting oneparticle reducible sixpoint vertices. The former class is represented by the recently introduced DMF{sup 2}RG approach [31], but also by the scaledependent generalization of the oneparticle irreducible representation (with respect to local Green’s functions, 1PILGF) of the generating functional [20]. The second class is represented by the fRG flow within the dual fermion approach [16, 32].more »