Origin of 'Hot Spots' in the pseudogap regime of Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4}: An LDA + DMFT + {sigma}{sub k} study

Journal Article · Sat Nov 15 00:00:00 EST 2008 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776108110137· OSTI ID:21241888

Kokorina, E E; Kuchinskii, E Z; Pchelkina, Z V ^[1]; Sekiyama, A; Suga, S; Tsunekawa, M ^[2]

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1. Russian Academy of Sciences, Institute for Metal Physics (Russian Federation)
2. Osaka University, Graduate School of Engineering Science (Japan)

The material-specific electronic band structure of the electron-doped high- T{sub c} cuprate Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} (NCCO) is calculated in the pseudogap regime using the recently developed generalized LDA + DMFT + {sigma}{sub k} scheme. The LDA/DFT (density-functional theory within local density approximation) provides model parameters (hopping integral values and local Coulomb interaction strength) for the one-band Hubbard model, which is solved by the DMFT (dynamical mean-field theory). To take pseudogap fluctuations into account, the LDA + DMFT is supplied with an 'external' k-dependent self-energy {sigma}{sub k} that describes interaction of correlated conducting electrons with nonlocal Heisenberg-like antiferromagnetic (AFM) spin fluctuations responsible for the pseudogap formation. Within this LDA + DMFT + {sigma}{sub k} approach, we demonstrate the formation of pronounced hot spots on the Fermi surface (FS) map in NCCO, opposite to our recent calculations for Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} (Bi2212), which have produced a rather extended region of the FS 'destruction.' There are several physical reasons for this fact: (i) the hot spots in NCCO are located closer to the Brillouin zone center; (ii) the correlation length {xi} of AFM fluctuations is longer for NCCO; (iii) the pseudogap potential {delta} is stronger than in Bi2212. Comparison of our theoretical data with recent bulk-sensitive high-energy angle-resolved photoemission (ARPES) data for NCCO provides good semiquantitative agreement. Based on that comparison, an alternative explanation of the van Hove singularity at -0.3 eV is proposed. Optical conductivity for both Bi2212 and NCCO is also calculated within the LDA + DMFT + {delta}{sub k} scheme and is compared with experimental results, demonstrating satisfactory agreement.

• OSTI ID: 21241888
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 107, Issue 5; Other Information: DOI: 10.1134/S1063776108110137; Copyright (c) 2008 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
ATOMIC FORCE MICROSCOPY
BISMUTH OXIDES
BRILLOUIN ZONES
CALCIUM OXIDES
CERIUM COMPOUNDS
COPPER OXIDES
CUPRATES
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
FERMI LEVEL
HIGH-TC SUPERCONDUCTORS
HOT SPOTS
HUBBARD MODEL
MEAN-FIELD THEORY
NEODYMIUM COMPOUNDS
PHOTOEMISSION
SELF-ENERGY
SINGULARITY
STRONTIUM OXIDES