NEGATIVE-U SUPERCONDUCTIVITY IN THE 2-BAND MODEL WITH THE PAIR-TRANSFER INTERACTION

被引:9
作者
YAMAJI, K
机构
[1] Electrotechnical Laboratory, Tsukuba, 305
来源
PHYSICA C | 1991年 / 177卷 / 4-6期
关键词
D O I
10.1016/0921-4534(91)90484-G
中图分类号
O59 [应用物理学];
学科分类号
摘要
The superconducting transition is studied in a two-band model which has an interband pair-transfer interaction between the conducting band and a hidden band not crossing the Fermi level. The interband ladder-diagram process enhances the effect of the pair-transfer interaction, remarkably reducing the effective on-site Coulomb energy and leading to high-T(c) superconductivity with a negative U. The isotope effect is shown to weaken with increasing T(c), if in addition we take account of the BCS interaction. The tendency of increase of T(c) with decrease of the Madelung potential difference DELTA-V(M) between Cu and O sites in cuprates is understandable in the present model.
引用
收藏
页码:303 / 309
页数:7
相关论文
共 25 条
[2]  
ASAYAMA K, 1991, SPR M PHYS SOC JPN 3, P173
[3]  
BATLOGG B, 1988, PHYS REV LETT, V60, P754, DOI 10.1103/PhysRevLett.60.754
[4]   DENSITY OF STATES AND ISOTOPE EFFECT IN BIO SUPERCONDUCTORS - EVIDENCE FOR NONPHONON MECHANISM [J].
BATLOGG, B ;
CAVA, RJ ;
RUPP, LW ;
MUJSCE, AM ;
KRAJEWSKI, JJ ;
REMEIKA, JP ;
PECK, WF ;
COOPER, AS ;
ESPINOSA, GP .
PHYSICAL REVIEW LETTERS, 1988, 61 (14) :1670-1673
[5]   NONZERO ISOTOPE EFFECT IN LA1.85SR0.15CUO4 [J].
BATLOGG, B ;
KOUROUKLIS, G ;
WEBER, W ;
CAVA, RJ ;
JAYARAMAN, A ;
WHITE, AE ;
SHORT, KT ;
RUPP, LW ;
RIETMAN, EA .
PHYSICAL REVIEW LETTERS, 1987, 59 (08) :912-914
[6]   MODIFICATION OF THE ISOTOPE EFFECT DUE TO PAIR BREAKING [J].
CARBOTTE, JP ;
GREESON, M ;
PEREZGONZALEZ, A .
PHYSICAL REVIEW LETTERS, 1991, 66 (13) :1789-1792
[7]   CORRELATION BETWEEN THE SUPERCONDUCTING TRANSITION-TEMPERATURE AND CRYSTAL-STRUCTURE OF HIGH-TC CUPRATE COMPOUNDS [J].
DELEEUW, DM ;
GROEN, WA ;
FEINER, LF ;
HAVINGA, EE .
PHYSICA C, 1990, 166 (1-2) :133-139
[8]   ENHANCED PAIRING INTERACTIONS IN A 2-BAND MODEL [J].
ENTINWOHLMAN, O ;
IMRY, Y .
PHYSICAL REVIEW B, 1989, 40 (10) :6731-6738
[9]   ELECTRONIC-STRUCTURE AND VALENCE-BOND BAND-STRUCTURE OF CUPRATE SUPERCONDUCTING MATERIALS [J].
GUO, YJ ;
LANGLOIS, JM ;
GODDARD, WA .
SCIENCE, 1988, 239 (4842) :896-899
[10]   THE OXYGEN ISOTOPE EFFECT IN BA0.625K0.375BIO3 [J].
HINKS, DG ;
RICHARDS, DR ;
DABROWSKI, B ;
MARX, DT ;
MITCHELL, AW .
NATURE, 1988, 335 (6189) :419-421