Untitled

0 downloads 0 Views 2MB Size Report
Page 8 ... 2. 2. 0. 0. 1. ( ). (. ) 2 t t. Q t. M dudv. u v. M du t u u κ κ. = - = -. ∫. ∫. ,. (39). (. ) 2. 0. 0. (, , ) .... Academician of RAS K.M. Salikhov (KFTI RAS, Kazan).
http://mr-kzn.ru/proceedings/mrschool2016.pdf

LECTURE NOTES f

Z14 ³ dtdsdu S1 (t , s, u )  S0 (t ) S0 (u ) .

R1

(37)

0

Direct calculation produces () 1

R1

() 1

(r) 1

R ,

R

Q(t )



R

Z14 4

³

f

0

dtdsdue  Q (t ) Q ( u ) e r < ( t , s , u )  1 ,

t 1 M 2 ³ dudv N u  v 0 2

M 2 ³ du (t  u )N u , t

0

M 2 ³ dt '³ du 'N t ' s  u ' .

< (t , s, u )

t

u

0

0

(38) (39) (40)

For preliminary qualitative understanding we should recognize, that essential range on t and u of the integrand is of order T2, while its duration on s has the order W c , because with increasing of s we have S1 (t , s o f, u ) o S0 (t ) S0 (u ) (or < (t , s o f, u ) o 0 ) that produces a rough estimation R1  Z14T22W c . If W c  T2 , then this estimation is sufficient, but opposite relation W c  T2  M 21/2 requires more refined analysis. Below, following to Refs. [5] and [3], we apply rather general form of the local field correlation function 32

N t

§ T W · 2T 0 ¨ ¸ . ¨ t2  T 2 W ¸ 2T 0 ¹ ©

(41)

This relation incorporates all existing qualitative information about correlations of dipole local fields on impurity nuclei taking into account existence of smooth quadratic in time evolution at t  T2T , its transformation into linear in time dependence at T2T  t  W 0 with consequent transformation to 3d-diffusional asymptotics N (t )  t 3/2 at t  W 0 . It is evident, that W c  T2T  W 0 here. It will be evident from the calculations that largest value has the term R1(  ) from (38). It can be rewritten as R1(  )



4 ³

Z14

T2 T

0

f

ds  ³ ds T2 T

³ dtdu e f

0

 Q ( t ) Q ( u )

e

< (t ,s , u )

 1

R1( )  R1(! ) .

(42)

Looking for orders of values we can approximate R1( ) and R1(! ) as R1( ) () 1!

R



Z14



Z14

4 4

³

T2 T

³

f

0

T2 T

ds ³ dtdu e  Q (t ) Q (u ) e ” and “