T????????????????

1
???????60?????(2005.3.24-27??????????????)
27aZC-1
T???????????????? ????????
??????CREST(JST) ??????????????
Lucent Technol., Bell Labs. Loren N. Pfeiffer,
Ken W. West
Outline 1.????? 2.GaAs T????? 3.????????????? 4.??
??????????????????? 5.???
2
????????
??????????1???????

• ???-????????????????
• ????????????

T?GaAs?????
1. cw??????????????????? 2. ????????????????????
??????
?????

• (???????????????)
• ???????????????????(cw??)
• --- ???????????????

3
????????????????? (T5 K)(???????)
n1D 1.2 x 105 cm-1 (rs 6.6 aB)
????????????? ????????
n1D 3.6 x 103 cm-1 (rs 220 aB) ???????
2.8 meV
Yoshita et al., cond-mat/0402526.
4
GaAs T???????(??????)
T?????
????????
?????????? MBE??
ref ???????????? by Y. Hayamizu et al.,
APL81, 4937 (2002).
5
??????????? --- wire ??
??? ps-TiSa laser (pulse 2 ps , hn1.598 eV )
?? ??????????? (????? 0.18 ns????????1.8
meV)
?????????
?????????
S-peak
ex.
????
?????
t 0.42 ns
? 2????? ???.
cf.
arm??
???????? ?????
? ??????? ???(S-peak)???.
arm QW??? ??????
6
?????????????????(cw??)
arm QW exc.
stem QW exc.
Exc. Power (mW/mm2) OD 0.2 step
Eexc 1.6939 eV
Eexc 1.6146 eV
spot exc. (f0.8 mm)
????????? ????????
?? ?????????? ???????????
7
??????????????????
??PL?
??-??????????
????? 0.8 mm/CCD pixel ???????? ???slit?
limit
???
?????? ??
8
???????-??????????
???_at_ grating 0nm slit 1mm
???
S-peak
ex.
?? ??
? E1.696 eV
? E1.648 eV
???????????!
9
?????????????
ex. peak
S-peak
(???)
P1mW
?????? ???????
ex.
S-peak (low energy side)
10
????????????????
????????
???????????? ??????? 1.652 eV
????????
11
????????????????
X-??
?????????
?
????????
e
?
???
?????????????armQW????????????????
?
X-??
1.652 eV
h
?
??????????e-h? ?????X-?? ???e-h e
????????
(?????????)
12
???
1. T??????????????

• ??????????????????? ??????
• ???????????
• ??????????????????
• ????????????????????????
• ??????????????

2. T????????????????????

• ????????????????? cw???????
• ?????????????????????
• ??????????????????????????
• ???????????

• ?????
• ???????????????????
• ???????????????????????

13
(No Transcript)
14
???????? - ??????? -
??? ps-TiSa laser (pulse 2 ps , hn1.652 eV )
?? ??????????? (????? 0.18 ns????????1.8
meV)
????PL?????
????PL?????
????
I0 5.6107 photons/pulse
0.6 ns
15
???????-??????????
???_at_ grating 0nm slit 1mm
????
????
???
???????? ????
????????
????????? ?????????
16
????????????????? (T4 K)
??? ??????? 0.8 mm ???????? 1.6146 eV
(arm????)
?? CCD binning???????????????????
????? ??????0.8 mm (CCD pixel
limit) ??????0.8 mm (?????
limit)
???????????
17
??????????(I)
??PL??
???????? vs. ?????
pl
plex
biexex
18
??????????(II)
????????????
pl
plex
biexex
19
??????????????(T30K)
???????????????
excited ????????(1.589 eV)
onset ???????????????
?????????? (?? by
Itoh)
20
??????????
above 510-2 mW (higher density regime)
High

• ?????????? (????????)

around 2-510-2 mW (high density regime)

• ???????
• ????????????????
• ???????? ????????

????
around 10-2 mW (intermediate regime)

• ???????????????????
• ??????? ??????? 2.8 meV
• superlinear???

below 10-4 mW (low density regime)
low

• ????????(1.582eV) 1???????

21
???????????????????

• ??????????????????????????????????????????

(1) ????????
n1D 3.6 x 103 cm-1 (rs 220 aB)
??????? 2.8 meV
(2) ???????????
n1D 1.2 x 105 cm-1 (rs 6.6 aB) ???????????????
????

• 1D ???????????

(1) ??????????????????( lt 2meV )
(2) ??????????????????
(3) ????????(????1D-DOS?????????)
??????????????????
( ???????????? )
22
????????????????

• ????????? (?)

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

• ?????????????? (?)

• (1) ?????? BGR????
• cf. ????? --- no energy shift
• ????????????????????
• (3) ????????????????????????

• ?????????2??????????????

23
1D???-????????????
???Mott?????
??????
????????????

• ????????(????)
• ?????????????

?????red-shift (BGR) ????????????

• ???????????????
• ?????????????BGR
• ????

eg. D. W. Wang and S. Das Sarma, PRB 64,
195313 (2001).

• ???????????????
• ???????????????
• ???????????

band edge
exciton level
?
????????????? ???????
24
????????????????
arm (cladding)
????????
arm (core)
wire
????????????
??????? (eV) Econf. (meV)
stem QW 1.6291 75.4
arm (cladding) 1.6105 78.7
arm (core) 1.6055 74.1
wire 1.5908 1.5908
10 AlGaAs 1.6437 (Eg) 81.1
????????
GaAs????????????????
25
??????????????
?????
????????????
??????? (eV) ???????? (meV) ???????? (meV)
??????? (eV) ??Eeconf ??Ehconf
stem QW 1.6291 75.4 34.7
arm (cladding) 1.6105 78.7 12.8
arm (core) 1.6055 74.1 12.4
wire 1.5908 60.5 11.3
10 AlGaAs 1.6437 (Eg) 81.1 43.7
arm (cladding)
arm (core)
wire
GaAs????????????????
26
?? - ??????????????
?? ps-TiSa laser, hn1.652 eV
6.2107 ph./pulse
?????
????????? ????????
?????????????
??????
0.33 ns
27
??????????
???????
???????
???
???????? (1.582 eV)
??????? 0.6 ns _at_5K
cf. stem, arm???? 0.2 0.3 ns
???
????? ???????? ?????
?????? ???? 0.33 ns
????? ??????????????? ????????
???????????
??????? ??????
stem, arm????????????? ???????????
28
??????????
T30K? ?????(?) ????????
29
???????????????????
????PL? (uniform exc., T5K)
uniform exc.
T5K
30
?????????????
??
1. ???????????????????????????? 2. ???????
???? 3. 1????????? ????????????
?????? 10 meV ????? 1.3 meV
Theory Citrin, PRL 69, 3393 (1992).
Exp. Akiyama et al., PRL 72, 924 (1994).
Gershoni et al., PRB 50, 8930 (1994).
??
31
???????????
???????
????
???
???????? (1.582 eV)
??????? 0.6 ns _at_5K
cf. stem, arm???? 0.2 0.3 ns
??1meV???????? ??????
???
????? ???????? ?????
?????? ????
????? ??????????????? ????????
?????????
??????? ??????
????????????????? ???????????
32
sub ps
10 meV
100 ueV
10 ps
wire ?? ???????????????????
33
???????????????????????
?????
?????????????????
?????
?????-???(?????)?? ?????-????
????????? ???Lorentzian not inversed Fermi
distribution not one particle 1D DOS
?????????? ????????????
??????????????????
34
??????????
Probability of Photon
Cavity length 500 mm
Probability of Electron
Hayamizu et. al. APL 81, 4937 (2002)
35
????????????????
???????-????????????
??PL?
???? ?? // ???? ?????????????
??????? ??????? ????? 0.8 mm/pixel
36
???????60?????(2005.3.24-27??????????????)
27aZC-1
T??????????????????
(??)
??????CREST(JST) ??????????????
Lucent Technol., Bell Labs. Loren N. Pfeiffer,
Ken W. West
Outline 1.????? 2.GaAs T????? 3.????????? 4.??????
?-?????????????? 1) ??????? 2) ???????
????????????????????? 5.???