High Tc superconductivity in MgB2 by nonadiabatic pairing -: art. no. 117003

被引:54
作者
Cappelluti, E
Ciuchi, S
Grimaldi, C
Pietronero, L
Strässler, S
机构
[1] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
[2] INFM UdR, Rome 1, Italy
[3] Univ Aquila, Dipartimento Fis, I-67010 Coppito, Italy
[4] INFM, UdR, Laquila, Italy
[5] Ecole Polytech Fed Lausanne, IPR LPM, CH-1015 Lausanne, Switzerland
[6] CNR, Ist Acust OM Corbino, Area Ric Tor Vergata, I-00189 Rome, Italy
关键词
D O I
10.1103/PhysRevLett.88.117003
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The evidence for the key role of the sigma bands in the electronic properties of MgB2 points to the possibility of nonadiabatic effects in the superconductivity of these materials. These are governed by the small value of the Fermi energy due to the vicinity of the hole doping level to the top of the s bands. We show that the nonadiabatic theory leads to a coherent interpretation of T-c = 39 K and the boron isotope coefficient alpha(B) = 0.30 without invoking very large couplings and it naturally explains the role of the disorder on T-c. It also leads to various specific predictions for the properties of MgB2 and for the material optimization of these types of compounds.
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页数:4
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