yamagata universityct(1−e −t/τ)!ηγ" 0 t τ =gγ! 0 t σ(t) t/τ σ(t)!gγ(t)! #t

5
σ 1 (t ) = Gγ 1 (t ) σ 2 (t ) = η γ 2 (t ) G η γ 1 γ 2 σ 2 σ 1 σ 1 σ 2 G η γ 1 γ 2 γ σ σ σ (t ) = σ 1 (t ) = σ 2 (t ) γ (t ) = γ 1 (t ) + γ 2 (t ) σ 1 (t ) = Gγ 1 (t ) σ 2 (t ) = η γ 2 (t ) γ (t ) = γ 1 (t ) + γ 2 (t ) γ 1 (t ) = 1 G σ 1 (t ) = 1 G σ (t ) γ 2 (t ) = 1 η σ 2 (t ) = 1 η σ (t ) γ (t ) = γ 1 (t ) + γ 2 (t ) = 1 G σ (t ) + 1 η σ (t ) γ 1 (t ) = 1 G σ (t ) dσ (t ) dt + 1 τ σ (t ) = G dγ (t ) dt τ η G G 5,=/ 4%$+)<: γ 1 (+0) = γ (+0) = γ 0 t γ(t) 0 γ 0 :?0293 t = +0 5,7 :?02;6?? !"'&"#02 γ 2 = σ 2 = η γ 2 = σ = σ 2 = (.>B8A15,-C γ 2 (+0) = 0 0293!"'&"#02D t σ(t) 0 Gγ 0 ? σ 1 (+0) = Gγ 1 (+0) = Gγ 0 σ 1 (t ) = Gγ 1 (t ) %$5,@* σ (t ) = σ 1 (t ) σ (+0) = σ 1 (+0) = Gγ 0 +)5, = %$5, σ (+0) = Gγ 0

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Page 1: Yamagata Universityct(1−e −t/τ)!ηγ" 0 t τ =Gγ! 0 t σ(t) t/τ σ(t)!Gγ(t)! #t

���������

���������

σ1(t) = Gγ 1(t)

σ 2 (t) = η γ 2 (t)

G

η

γ 1

γ 2

σ 2

σ1

σ1

σ 2

“ �”

“�����”

�����

�����

G

η

γ 1

γ 2

γ

σ

σ

σ (t) = σ1(t) = σ 2 (t)

γ (t) = γ 1(t) + γ 2 (t)

σ1(t) = Gγ 1(t)

σ 2 (t) = η γ 2 (t)

γ (t) = γ 1(t) + γ 2 (t)

γ 1(t) =1Gσ1(t) =

1Gσ (t)

γ 2 (t) =

1ησ 2 (t) =

1ησ (t)

γ (t) = γ 1(t) + γ 2 (t)

=1Gσ (t) + 1

ησ (t)

γ 1(t) =

1Gσ (t)

dσ (t)dt

+1τσ (t) = G dγ (t)

dtτ ≡

ηG� ��

�� G���������������

5,=/

4 �%$�����+)�����<�:γ 1(+0) = γ (+0) = γ 0

t

γ(t)

0

γ0

���“:?”0293 t = +0 �5,�7���:?02����;�6?�?��!" '&"#�02������

γ 2 = ∞ σ 2 =η γ 2 = ∞ σ =σ 2 = ∞���(.>B8A1�5,�-�����C�

γ 2 (+0) = 0���0293�!" '&"#�02����D

t

σ(t)

0

Gγ0 ?

σ 1(+0) = Gγ 1(+0) = Gγ 0σ 1(t) = Gγ 1(t)%$�����5,�@*��

σ (t) =σ 1(t) σ (+0) =σ 1(+0) = Gγ 0+)�5, = %$�5,

σ (+0) = Gγ 0∴

Page 2: Yamagata Universityct(1−e −t/τ)!ηγ" 0 t τ =Gγ! 0 t σ(t) t/τ σ(t)!Gγ(t)! #t

!�)�

t > 0 �� γ (t) = γ 0 ����%+������dγ (t)dt

= 0

σ (t) = Gγ 0e− t /τ

��� t > 0 ��

G(t) = σ (t)γ 0

= Ge− t /τ

' t > 0 -���.�!�����* �

dσ (t)dt

+1τσ (t) = 0 dσ (t)

dt= −

1τσ (t)���

σ (t)∝ e− t /τ �� σ(t) �"#,#

�$������(&�� σ (+0) = Gγ 0

G(t)

t0

G

�����

G(t) =Ge− t /τ t > 00 t < 0

⎧⎨⎩

τ ≡ηG

τ

G/e

������

�����

G(t)G(t)

G

t t00

���� �����

�������� γ1(t)

t0

γ0

γ1(t)����

σ1(t) = Gγ 1(t)

σ 2 (t) = η γ 2 (t)

=

σ (t)

=

γ2(t)

t

γ0

0

γ2(t)�����������

γ2(t)γ (t) = γ 1(t)+ γ 2 (t) = γ 0

�������

log t

10−1G

10−2G

10−3G

10−4G

10−5G

10G

G

10τ 102τ 103τ10−1τ10−2τ10−3τ τ

log G

( t)

G(t)

G( t)

t

G(t)

0.2G

0.4G

0.6G

0.8G

G

0τ0 2τ 3τ 4τ 5τ 6τ

�����

�������

Page 3: Yamagata Universityct(1−e −t/τ)!ηγ" 0 t τ =Gγ! 0 t σ(t) t/τ σ(t)!Gγ(t)! #t

#/1'*

dσ (t)dt

+1τσ (t) = G dγ (t)

dt    (1)Maxwell����

���)"�3�

γ (t) = γ 0 cosωt#/1'*.$�4���

�!��2������

σ (t) = acosωt − bsinωt%,��� 2���&�5 �2�

�(������ ��!�� (1) �+�0����a, b�-$�����

$# ��"

dσ *(t)dt

+1τσ *(t) = G dγ *(t)

dt   (1*)(1)�$# ��

γ (t) = Re γ *(t)⎡⎣ ⎤⎦γ *(t) ≡ γ 0eiω t

(1*) �%�$# ��� σ*(t) �!�������

dRe σ *(t)⎡⎣ ⎤⎦dt

+1τRe σ *(t)⎡⎣ ⎤⎦ = G

dRe γ *(t)⎡⎣ ⎤⎦dt

(1*)��&�� '����

σ (t) ≡ Re σ *(t)⎡⎣ ⎤⎦

(1*) �% σ*(t) �!����

�(1)�% �����

����$# ��

�(1*)��!�γ *(t) ≡ γ 0eiω t

dσ *(t)dt

+ 1τσ *(t) = Giωγ 0e

iωt

+� (1*) �/����-���

iωσ 0*eiωt

1τσ 0*eiωt

iω + 1τ

⎡⎣⎢

⎤⎦⎥σ 0*eiωt = Giωγ 0e

iωt���

�0�*1�%(�"� eiωt

σ 0* = G iω

iω + 1τ

γ 0 = Giωτ1+ iωτ

γ 0

�#� )�$ ���.���

���,��/����

eiωt

��/�

σ *(t) = σ 0*eiω t

�' ����&��!����

σ *(t) = σ 0*eiω t = G iωτ

1+ iωτγ 0e

iω t

= Giωτ 1− iωτ( )1+ iωτ( ) 1− iωτ( ) = G

iωτ +ω 2τ 2

1+ω 2τ 2

(1*)���

= G*(ω )γ *(t)

= ′G (ω ) + i ′′G (ω )

′G (ω ) = Gω 2τ 2

1+ω 2τ 2′′G (ω ) = G ωτ

1+ω 2τ 2

���� ���

G*(ω ) = G iωτ1+ iωτ

������

Page 4: Yamagata Universityct(1−e −t/τ)!ηγ" 0 t τ =Gγ! 0 t σ(t) t/τ σ(t)!Gγ(t)! #t

′G (ω ) = G ω 2τ 2

1+ω 2τ 2′′G (ω ) = G ωτ

1+ω 2τ 2

ωτ 1

ωτ 1

1+ω 2τ 2 ≈1

1+ω 2τ 2 ≈ω 2τ 2

′G (ω ) ≈Gω 2τ 2 ′′G (ω ) ≈Gωτ

′′G (ω ) ≈ Gωτ

′G (ω ) ≈G

′G (ω )∝ω 2 ′′G (ω )∝ωMaxwell /

�������

G'( ω

) , G

''(ω

)

ω

G''(ω)

G'(ω)

0

G

0.8G

0

0.6G

0.4G

0.2G

0

0.2

0.4

0.6

0.8

1

-3 -2 -1 0 1 2 3

log ωτ

G'( ω

)/G, G

''(ω

)/G

������

����� ��

�������

����������

������

log G

'(ω) ,

log G

"(ω

)

log ω

10τ

G

10G

10−2G

10−3G

10−4G102

τ103

τ10−3

τ10−2

τ10−1

τ

10−1G

G'(ω)

G''(ω)

�� �

��2

��1

/%8'��()/%�

γ (t) =0 (t < 0)γ 0 (t ≥ 0)

⎧⎨⎪

⎩⎪.# t = 0 �!(���6* /%�8'��9

t→∞ �()0-�7�����9 dσdt

→ 0 (t→∞)

σ →Gτ γ 0 =η γ 0

σ (t = 0) = 0/%8'3+���,$�21�����9

dσ (t)dt

+ 1τσ (t) = G γ 0

---(1) ���5��

dσ (t)dt

+ 1τσ (t) = G γ 0t > 0 �

4*�� ��/"�&�,$

Page 5: Yamagata Universityct(1−e −t/τ)!ηγ" 0 t τ =Gγ! 0 t σ(t) t/τ σ(t)!Gγ(t)! #t

σ (t) ≡η !γ 0 − Δσ (t)

dσ (t)dt

+ 1τσ (t) = G !γ 0 ---(1)

dΔσ (t)dt

+ 1τΔσ (t) = 0

Δσ (t)∝ e− t /τdΔσ (t)dt

= − 1τΔσ (t)

t=0 ( σ(t=0)=0 Δσ (t = 0) =η !γ 0 Δσ (t) =η !γ 0e− t /τ

σ (t) =η !γ 0 1− e− t /τ( )

2 )

( ) (

σ (t)η !γ 0

t / τ

σ (t) =η !γ 0 1− e− t /τ( )

3 t >> τη

σ (t) !η "γ 0

4

e− t /τ ! 1− tτ+ ...t << τ )

γ (t) = !γ 0tt (

σ (t) ! Gγ (t)

σ (t) =η !γ 0 1− e− t /τ( ) !η "γ 0 tτ = G !γ 0t

σ(t)

t/τ

σ (t) ! Gγ (t)

t << τ)

G(