凝聚态物理暑期学校1-Lecture2Superconductivity.ppt

Superconductivity
One of the most elegant phenomenon and beautiful story in Condensed Matter Physics
封东来
超导体
有些金属和化合物在降到接近绝对零度时，它们的电阻率突然减小到零，这种现象叫超导.
0.05
0.10
4.10
4.20
4.30
*
*
*
*
超导的转变温度
T/K
R/
***在4.2K附近电阻突然降为零
BCS理论
1980’s 中期，发现“高温”超导体（化合物超导电性）
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
Conventional SC:
Phonons mediated superconductivity
Year of Discovery
Transition Temperature (K)
BCS Theory
C60
MgB2
History of Superconductivity
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
Instinct !
H. Kamarligh Onnes and Tuyn. Leiden Commun No.160 (1922)
"to trace a possible difference in the vanishing point (of resistivity) of Pb and Uranium Pb (Pb-206 isotope). Regarding a difference of vanishing point temperature for isotopes, it seemed not impossible that the occurrence of the superconductivity might be influenced the mass of the nucleus"
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
HTSC:
New mechanism?
Conventional SC:
Phonons mediated superconductivity
Year of Discovery
Transition Temperature (K)
BCS Theory
C60
MgB2
History of Superconductivity
Hg-Ba-Ca-Cu-O
Tl-Ba-Ca-Cu-O
Bi-Sr-Ca-Cu-O
Y-Ba-Cu-O
La-Ba-Cu-O
Hg-Ba-Ca-Cu-O (pressure)
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
4He
3He
Lev D. Landau
Pyotr L. Kapitsa
David M. Lee Douglas D. Osheroff Robert C. Richardson
Anthony Leggett
Superfluidity
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
H. Kamerlingh Onnes John Bardeen Leon N. Cooper J. Robert Schrieffer
Ivar Giaever Brian D. Josephson Alexei Abrikosov Vitaly Ginsburg
Superconductivity
Donglai Feng “Electronic Structure of Strongly Correlated Systems”
Deep concepts in superconductivity
- C.N. Yang: Off-diagonal-long-range-order
- P.W. Anders