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5. BCS??????

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Title: 5. BCS??????


1
????
?? ???
2
1. ?????????
2. ????????????
3. ?????????
4. ????????????????
5. BCS??????
6. ????????? ?????????
7. ????????
8. ??????????
9. ???????
3
? ???????
1908?,???????????? ( Hei- ke Kamerlingh
Onnes,1853-1926 ) ?????
?? ??? ???????????? ?? ? ?,?? 4.2 K ???
??,??????,???????,? ?????????????,???????
?????????????????????
1911?,??? ??????????, ??????????????????
?,? ????????????????????? ???????????? 4.2 K
???,??
4
????????? ??!
???????, ????????? ??????????
??????? ????????? ???????1913 ????????? ??
5
? ??????????
1. ???????? Tc
????????,???????,? ? ??????? ,?? ?? ??
??? ( super-
?????????????
conducting state ),
??? ( superconductor ) ?
???????????????? ??? ??? (
superconducting critical temperature ),
? Tc ???
???????????
6
(No Transcript)
7
??????? ????
8
????? ??????
9
?????????? 0? ??????? ? 10-10 ??
??????? 10-23Ocm ?? 0? ?, ?????????
1.610-6 Ocm ,??? ???????????
2. ???????? Hc
??????????????????? ?,??? ??? ??? ????
,???? ????????????????????,
? Hc ???
?? ????,
???????????????????
10
???
T Tc ?,Hc 0
T ? 0 ?, Hc ? ???????? ???????, ???????? ????
Hc ??? ? ????????, ???? T ??,
Hc ( T ) Hc ( 0 )
1 - ( T /Tc ) 2
Hc ( 0 ) ? T ? 0 ???????
11
(No Transcript)
12
3. ???????? Ic
????,???????????,?? ??????????????,??????
? Ic ???
??,??????? ????,
Ic ?????? T ??????,
? Tc ?,
Ic ???
? ?????
1933 ?,?? ? ? ? ? ? ? ? ( W.F.
Meissner,1882-1974 ) ??????? ( R. Ochsenfeld )
??????????????? ?,????????????????,??
13
???? ???? ???? ??? ??,? ???? ???? B 0 ?
?? ??,?
???????????????????? , ????????,????? B0 lt Bc,??
14
? B ??? ??,? B 0 ??? ????? ????? ????? µr
-1 ( µr lt 0 , ???,?
?????? ) ,????? ? ? ? ? ? (
perfect diamagnetism )???? ????? ( Meissner
effect ) ?

15
???????,??????????? ????????? ??? ?
??????? B ??????
????
???????????? ????? ?? ?????????????? ?
?????? ??????????? ,???????? ?
???? ??? ?? ??? ??? ? ???? ??
????????????? ,????? ????????
,????????????
16
???????? ,???????????? ??? ,???????????,????? ????
17
???? ?????? ???,?? ?????? ???????
???? ??,??? ?????? ?????? ?????? ??????
?????????
18
? ??????????
1. ?????
??????????????????? ?????????????????????
??????,?????????????? ????,???????????????? ??????
?????????????,? ?????,??????????????, ?????? T
?? Tc ???,?????, ?????????????,??????? ??????????
?, T ??,????? ???? T ?????????????,??
19
???????????????????,? ? ????? ?
2. ?????
1950?,??????????????? ?,????????????
??????? ???????????????????,? ??? Tc
????????????????? ????
Tc ?
???????, Tc ???????????? ??????? M ? 199.5 ???
203.4 ??? ????, Tc ? 4.185 K ?? 4.146 K ?
20
??????????????????? ??,??????????,???????
?

??????,??? ????????? ?????????????,????
Tc ?? ?????????????????
???????????????????? ???
21

3. ???
1956????,???? ???? ( Leon North Cooper ,
1930-) ??????????? ?????????????,?????? ?????????
,??????????? ??? ,???????? ???? ?? ? ??
??? ?

????????,?????????? ??????????????
22


4. ????? BCS ??
( ????? )
1957?,???? ( John Bardeen ,
1908- 1991,?? )????? ? ????? ( John Robert
Schrieffer ,1931- ,?? ) ?????? ?????????,?????
BCS ???
???????
??????????????????? ?????,???????????????
? T gt Tc ????,??????????? ??,?????????????????? ?
,???????????????
23
???? T lt Tc ? ,?????????

BCS?? ??,? ???? ???? ??,? ???? ???? ????,
??????????,?????????? ????,???????????????? ??????
???????,???????
24
?????????,?????????? ??????????????,?? ??
, ???????????????,????? ????????????????????? ???
???,?????????????? ???????,???????????,? ?????
??? ????? ,????? ???????????? 10-6 m
,????? ????? 10-10m,???????????? ?????????????????
??,? ???????????????????,? ??????????????
?????? ?????
25
(No Transcript)
26
5. ????
?????? F??? H??????? ?????,? 1935
??????????? ??????????? ?? ???? ??? ?? ???? ?
??????
ns ???????
m 2me ??????
js ??????
q -2e ????????
27
???????????????????
????????????? jn sE ?
??????
js
B
????????????????,?? ????????????,????????
????????
????????? ( ???????? ?????,??????????????
?
?????????????)
28
?????????????????,
E 0
???????
????????????????,? ??????????????????
???????? js ? B ????????
??????
????,?????????
? 50 nm ?
?? ??????,????
29
? ??????
??20??30???,?????????,
????????????,????????
?????????? ?????????, ?????????? ??,??????? ??,???
???? ???????,?? ?????????? ??????????
Hc1 ? Hc2 ?
???
30
1. ??????
???????? Hc ??????????
???????
???????
2. ??????
?????? ?? Hc1?Hc2 ,

???????? ???????? ????????

??,????? ???
31
???????? ???????? ? ?? ??????? ????
(1) ????????
?????,????????????? ??????????,????
???? ?
????????,????????,? ?????????????????,???
????????????,???????? ???????
32

????????????,??????
????,? ?????? ?????? ?????? ?????, ?????? ????,? ?
????? ??????
?????? ???
33
(2) ?????????
????(fluxon)
F.???1950??????,?????? ????????? ,
????????f0 hc/e ?
? 20 ?? 60 ???,????????? ?????????,??
F.???????? ?????????????,???????
?? 2e ,??
f0 hc/2e ?
?????????
34
???? ?????? ?????? ?,???? ?????? ?????, ??
???? ????
?????????????,?????
?????????,?????????????,??????????????????????????
,????????????
???????
????????? ?
35
??????? ,????? 1961 ??? ????????? ??? (
Nb3Sn ) ?? ? ???????? ? ? ? ? ( superconducting
magnet ) ??????????????,?? ???????????
36
? ??????
1. ??
??????????, ?????????,??? ????????????? ??
??????????? ??? ?????
2. ????
?????,????? ??????,?????? ??????? ??
?? ??????,??????
37
???????,????????????, ??????,?????????????? ???,??
??????????????? ??????????,?????????, ?? ?????
1959?, ?????? ?????? ? (Ivar Giae-
ver,1929- ) ?????? ??,??? ??????
38
??????? ?,????? ??????? ??????? ??????? ??????? ??
,????
???????????,???????,? ????????????????????? ??????
,?????????????? ?????????????????????? 1960??,????
??????????,? ???????
39
????????,?????????? ?????????????
??????????????????? ???????
3. ?????? ( Josephson effect )
1962?,??????????????? ? (Brain David
Josephson ,1940- ) ????, ?????????-??-???????? ???
????????????????? ??????????????????,?? ?????????
??,????????,
????????????(d.c. Josephson effect)?
40
?????????? V0 ?,?????? ?? ?????? ??,
1µV ????????????? 483.6 MHz ( ???????????
)????????? ?????? ( a.c. Josephson effect )?
?? ,???????????????? ??1963????( P.W.
Anderson )?????? ????????? ( ???????? ),?? ?( S.
Shapiro ) ??????????? ( ??? ????? )?????????
???????
41
?????????????? ( Leo Esaki, 1925-
,??,?????????? ) ??? ??????????1973 ??????????
???????,?????????-? ??-?????????????????,
??????????? ??? ????? ??? ( ???????
),????????? ?? ( ??????????????
),??? ?,????????????? ? ?? ? ? ??,?????????????
,???? ????????????
42
(No Transcript)
43
? ????
1986?4?,????? ( J. Georg Bednorz , 1950 -
,?? ) ? ???? ( Karl A. Muller , 1927 - ,?? )
???????????? Ba-La-Cu-O ??????? Tc ????
??????,?????????????? ????????????,???????? ?????
???Tc ???? 33K ?
?????????????????? Tc ????,?????1987?????
?????

??????????????????? ?????????????????
44
1987?2?24????????,????? ?????????? (
Y-Ba-Cu-O ) ??? Tc ???? 92.8 K??
,??????????? ????????????? 77.3 K ,???? ??? 100
?,????? 63 ?,?????? ?????,??????????????
?1986?4??????????????? ?? ????
??????????????? ? ,?????????????????? ? ??? ?

45
??????????????????? ???????,??????????100?
? 1998 ?7?,??????????????? ?????????? 1
?????????? ???????,?????? 1200 ?
,?? ??????????????????????
2000 ? 11? 26???????????? ?,??????????????
??? ?? ??????????????? ,????? ???????????????
,????? ????


?????????????? 116 ?,?
46
3.6 ??,?? 0.28 ?? ,????????, ??????????,77 K
???????? ????? 12.7 ???
???????? 100 ????????? ???????????????????
?? ??????????????????,?? ??? 20 ,???????????
??? ?,????????,???????????
????? 2001 ??????? ,? ?????????????? ?
2001 ??? ?????????????????,??? ???????????????????
47
? ?????
????????? ????
? ?????
1. ????
???? ???????? ??????? ???,??????? 103
Amm-2 ??,?? ????????????
(1) ???????????? ? ???? ???????,?????????
?? B 30 T ?


48
??????(???????????)
49
?? 9 ?,????????????? 2000 ????????? TEXT-U
??????? ????????????? TEXT-U ??? ?????
,??????????????? ???????????? ,???????? ??,???????
??????????
???? TEXT-U ?????????? ??????

50
(2) ?????? ( N M R ) ???,??? 110 T
??????
2003???????????????74? ?????? ?? ????
???70???? ??? ?? ????? ,????????? ?????????????
???????? ??? 130 ???????
??????????????????? ?????????????,????,??
????????????????????? ???,?????????
51
(3) ???????????,??? 100?
???????? ??? ???? ,?????? ? 25 50,??? ????
30 50, ?????????
(4) ??????? ???????
?????
???????? ?????????? ?????
52
???????????????? ??? ? ??? ??,??????? ??
? ??? ???
??????????
???????????,??????? ???,???????????????,?
???????,????????????? ???,????????????????? ??????
?????????????,? ?????????,???????
53
????? ?????,? ??????? ??????? ??????? ????
??? ??????? ???,??? ??????? ??????? ??,???? ??????
? ????,??
54
??????? ??????? ??????? ??,???? ??????? ?,??,?? ??
????? ???????
55
??? ????? ????? ????? ????? ????? ?,??? ??
??? ????10 mm ??? ?????? ????? ?????
56
??????? ( ?????? ) ,?????? ??? ,??? ,???????????
?? ?????? ,??????? ,??? ??? ???????
??????????????????? ??????,?????????
57
??????????????????, ???????????????,?????
???10?????????????,??? ????????????????????? ?????
???????????????????? ????????????
,???????? ?,????? 1 ?? ??????????? ??,??????,?????
?????? ?? ???,?? ?????? ????? ?????? 20 ?,??
( ?? ) ??? 15 ?, ?? 3 ?,????? 10 ?,? 44 ???,? ??
130 ???
58
?? 2000 ????????????,? ?????????????,?????
?? ????????
??????????????????? ???????????????,?????
??????????????????? 2.2 ???????????????

??2008?????????,????? ????????,??24.8???
59
????????????,?????? ? 2
??????,???????????? ?,? 31???????2003???1???? ????
??? 505 ??,?? ??? 430 ? ???????????????
60
(No Transcript)
61
(No Transcript)
62
??????
63
??????????????,???? ????????,????????????
??????????????,???? ??????????????,??????
???????????
??????????????????? ?????????,???????????
????????????????????? ?????????,?????????,? ??????
???????,??????? ????????????????????, ????????????
????????? ?????????????
64
(5) ????,???? LI2/2 ?

2. ????
????????????????
(1) ????,????????????? ??????????????????
10-12 s ?? ,????? 10-12 W ???
?????? ????????????????????? ?????,?????
4.210-11-4.210-12 J s-1 ?


(2) ??????? ( SQUID )???,?? ?????????????
????? ??? ?????,????? 10-15 T ? ????,
65
??????????? ????????
J1? J2 ??? ? ????,????? ? i1? i2
?????? ?,?? ??? i ?? ???????
???????? ?,???????? F ,?
i i1 i2 i0cos(pF/F 0 )
66
i i0cos(pF/F 0 )
i0 ??????? ??,?????,F ???F0 ? 2 ??,i
????????? ? ?F0 ???????, ???? i ??? ?? ??,??,
SQUID ?????????
67
(No Transcript)
68
(No Transcript)
69
(3) ?????,?????? KJ 2e/h, ? Vn n
f/KJ ??????????1990 ?, ????????????? KJ -90
483597.9 GHz/V ,?????????? ( ?? )?
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