H =S Ji,i 1 SiS i 1

1
???????????? ???? ?????????? ????????? ?
????-??????? ??????????
?.?.???????
?????????????? ???????? ?? ?????
?????????????????? ????????? ? ???????? ????????
2006/2007 ???????? ????
2
???????????????? ????? ? ???????? ?????????
????????? ???????????????????
H S Ji,i1 SiS i1 H Ji,i1 S
SzjSzj11/2(SjS-j1 S-jS j1 ) Si
SxiiSyi Si Sxi-iSyi
??? ???????????? ???????? ????????? ??? J gt 0
-
-
?? ??? ?? ???????? c?????????? ???
?????????????
3

??????? ?????? S1/2 (????? ????)
0
-1/4
-ln21/4 (H.Bethe, 1931)
ltSgt0
z
x

-3/4
-E/NJ
4
?????? (????????? ???????????)
???????????? ???????
?????? ??????? ?????? Ѕ. ?.?????? 1993
5
??????????? (????????? ?????????)
?????? (????????? ???????????)
?????? ??????????? ? KCuF3
D. Tennant et al 2000
6
????-??????? ??? ???????
?????????????? ??????? S1/2
????????????? ??????? (S1)
????????, ? ????-????????????? ?????????
g.s.gt
i0hihi0hih0ihih0ihihihih
0.41J
ltSgt 0
x 7
Spin gap
c
SPIN-GAP DdJ
T
ltSzgt0 x v/D
J
7
?????? (????????? ???????????)
???????? ????
?????? ??????????? ??????? ?????? S1 ?.??????
PRB 1993
8
(No Transcript)
9
???????????? ??????????????? ????????? ?
???????????

• ?????????? ??????? ?????? S1/2 ???????????
• TN (JJ)1/2
  

J
2. ????-??????? ??????? ?????????, ????
?????????? ???? J,DltD.
Interchange exchange / exchange
Anisotropy / exchange
Sakai and Takahashi diagram from Zheludev et al
PRB 2000
10
Regnault et al JPCM 1993
11
??????? ??????? c S1/2 ?? ?????? ??????? ??????
S1
Hagiwara et al PRL 1990
12

?????? (????????? ???????????)
S1/2
Miyashita Yamamoto PRB 1993
13
(No Transcript)
14
Structure and susceptibility of a Haldane magnet
(Pb2)
Uchiyama et al PRL 1999
15
h DPPH-label
A.Smirnov et al PRB 2002
16
A.Smirnov PRB 2002
17
Length of the fragment Lfa/x
ltSzigt
Length of the cluster
i
18
Increase of the linewidth with concentration indic
ates contacts of clusters
At the average chain fragment length of 50a
(x2) about a half of fragments are shorter
then 20a HENCE
DH
Lcl10a
19
Regnault et al JPCM 1993
20

Spin S1 in a crystal field
S1/2
21
(No Transcript)
22
A.Smirnov et al JMMM 2004
23
ltSzgt
24
Impurities
Triplets
25
Pb(Ni0.96Cu0.04)2V2O8, 9.5 GHz
26
(No Transcript)
27
Collective ESR mode Triplets Chain Ends
A.Smirnov JMMM 2004
28
??????????? ??????? ?????????? ?????????
  ??? ??????????? ?????? S1/2. ??? ???????????
?????? S1 ?????????? ??????????????
?????????. ???????????? ???? ??????????
??????????? ? ??????????? ?????? S1/2 ?? ??????
?????????? ???????? ???????.????????????
???????????? ? ??????????? ?????? S1/2 ????????
??? ????????????? ? ??????????.
29
3D dimer net in monoclinic TlCuCl3
spin-gap
These excitations are also triplets S1
Magnetic excitations in the spin-gap system
TlCuCl3 PHYS. REV. B 65, 094426 (2002) A. Oosawa
et al.
30
??? ???-???? ????????? ????????? ????????
???????? ? ????????????? ??????????
?????? 2 ??????? ???????? ???? ??????? ?????????
?????
31
PRL 2000 Bose-Einstein Condensation of Dilute
Magnons in TlCuCl3 T. Nikuni, M. Oshikawa, A.
Oosawa, and H. Tanaka
32
?????????????? ????????? ?????
(!!??) ?????????????????? ??????? ? TlCuCl3
33
???????? ????? ?????? S1/2 ? ????????? TlCuCl3
????????????? ??????????? ????????? ????????????
??????????
?????????? ?????????????? ?????? ??????????
?????????, ??????????????? ????????????? ??????
S1 ? ??????????????? ???? ??????????? ???
?????????? ??????????? ? ?????????? ??????? ??
?????? S1/2.
H10-2, f30.05???
V.Glazkov et al PRB 2004
34
TlCuCl3 ??? ??? ????????? ???????????? ?
??????? ?????.
? ??????? ????? ??????????? ??? ?????????? d
??? HltHc e ??? HgtHc ??? ????????? ???????????
??? ?????????? ????????? ? ??????? ??????? ?????.
Hb, f26 ???
V.Glazkov et al PRB 2004
35
TlCuCl3 ESR

• a, b, c - ???????? ????? ?????????????
  ??????????????? ????? ??????????? S1
• d - ??????? ????? S0 ? Sz-1
• e - ????

????????????? ???????? ????
????
?????- ?????????????? ???????
V.Glazkov et al PRB 2004
36
TCuCl3 ????????? ???????? ???????????????????
?????????
H10-2
V.Glazkov et al PRB 2004
37
??????????? ???????? ????? ?????????????
?????????? ???????????
???????????
????????? ????
38

???????? ??????? ??????????? ????? ? ?? ???????.
?????? ?????? ???? ???. (???????? ?????????? ????)
????-????????? ????????? ???????. ??? HgtHsf
?????? ???? 2-?????????????? ??? f1(?H)2
const11/2 f2const2 const1,2(HA1,2HE)1/2
39
???????? ??????
??????????? ???? S1/2 ????????????? ?????????
?????? S1. ??????????? ???? S1 ?????????????
????????? ?????? S1/2 ??????????? ???? S1
????????????? ????????? ?????? S1 ???
?????????? ???????? ????????? ???????????
????-???????? ?????????, ??????? ?????????
????????????? ???????????? ???? ????????
??????????? ????????? ???????? ? ??????????????
????? ??? ???? (????????? ?????? ?????????
???????)
??????? ?? ????????