Origin of strong correlations and superconductivity in NaxCoO2

被引：21

作者：

Khaliullin, Giniyat ^{[1
]}

Chaloupka, Jiri ^{[1
,2
]}

机构：

[1] Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany

[2] Masaryk Univ, Fac Sci, Dept Condensed Matter Phys, CS-61137 Brno, Czech Republic

来源：

PHYSICAL REVIEW B | 2008年 / 77卷 / 10期

关键词：

D O I：

10.1103/PhysRevB.77.104532

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We propose a minimal model resolving a puzzle of enigmatic correlations observed in sodium-rich NaxCoO2 where one expects a simple, free motion of the dilute S= 1/2 holes doped into a band insulator NaCoO2. The model also predicts singlet superconductivity at experimentally observed compositions. The model is based on a key property of cobalt oxides-the spin-state quasidegeneracy of CoO6 octahedral complex-leading to an unusual physics of, e. g., LaCoO3. We show that correlated hopping between t(2g) and e(g) states leads to the spin-polaron physics at x similar to 1, and to an extended s-wave pairing at larger doping when coherent fermionic bands are formed.

引用

页数：6

共 33 条

[1] THE RESONATING VALENCE BOND STATE IN LA2CUO4 AND SUPERCONDUCTIVITY [J].

ANDERSON, PW .

SCIENCE, 1987, 235 (4793) :1196-1198

[2] Magnetic ordering and spin waves in Na0.82CoO2 -: art. no. 157205 [J].

Bayrakci, SP ;

Mirebeau, I ;

Bourges, P ;

Sidis, Y ;

Enderle, M ;

Mesot, J ;

Chen, DP ;

Lin, CT ;

Keimer, B .

PHYSICAL REVIEW LETTERS, 2005, 94 (15)

[3] Charge ordering and magnetopolarons in Na0.82CoO2 -: art. no. 167003 [J].

Bernhard, C ;

Boris, AV ;

Kovaleva, NN ;

Khaliullin, G ;

Pimenov, AV ;

Yu, L ;

Chen, DP ;

Lin, CT ;

Keimer, B .

PHYSICAL REVIEW LETTERS, 2004, 93 (16) :167003-1

[4] Muon-spin rotation study of magnetism in NaxCoO2 single crystals with 0.78≤x≤0.97 [J].

Bernhard, C. ;

Niedermayer, Ch. ;

Drew, A. ;

Khaliullin, G. ;

Bayrakci, S. ;

Strempfer, J. ;

Kremer, R. K. ;

Chen, D. P. ;

Lin, C. T. ;

Keimer, B. .

EPL, 2007, 80 (02)

[5] NMR study of the magnetic and metal-insulator transitions in Na0.5CoO2:: A nesting scenario [J].

Bobroff, J ;

Lang, G ;

Alloul, H ;

Blanchard, N ;

Collin, G .

PHYSICAL REVIEW LETTERS, 2006, 96 (10)

[6] Direct observation of strong correlations near the band insulator regime of Bi misfit cobaltates [J].

Brouet, V. ;

Nicolaou, A. ;

Zacchigna, M. ;

Tejeda, A. ;

Patthey, L. ;

Hebert, S. ;

Kobayashi, W. ;

Muguerra, H. ;

Grebille, D. .

PHYSICAL REVIEW B, 2007, 76 (10)

[7] Structural details and magnetic order of La1-xSrxCoO3 (x≤0.3) [J].

Caciuffo, R ;

Rinaldi, D ;

Barucca, G ;

Mira, J ;

Rivas, J ;

Señarís-Rodríguez, MA ;

Radaelli, PG ;

Fiorani, D ;

Goodenough, JB .

PHYSICAL REVIEW B, 1999, 59 (02) :1068-1078

[8]

CHALOUPKA J, UNPUB, P14511

[9] Magnetic properties of spin-orbital polarons in lightly doped cobaltates [J].

Daghofer, M. ;

Horsch, P. ;

Khaliullin, G. .

PHYSICAL REVIEW LETTERS, 2006, 96 (21)

[10] Charge ordering, commensurability, and metallicity in the phase diagram of the layered NaxCoO2 -: art. no. 247001 [J].

Foo, ML ;

Wang, YY ;

Watauchi, S ;

Zandbergen, HW ;

He, T ;

Cava, RJ ;

Ong, NP .

PHYSICAL REVIEW LETTERS, 2004, 92 (24) :247001-1

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