90 lines
2.8 KiB
Fortran
90 lines
2.8 KiB
Fortran
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!
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!=======================================================================
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!
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MODULE MATERIAL_CL
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!
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! This module defines the material characteristic lengths
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!
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USE ACCURACY_REAL
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!
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IMPLICIT NONE
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!
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REAL (WP) :: EMFP,FWL,PCL,THL,ML,CR,DL,TFL
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!
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END MODULE MATERIAL_CL
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!
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!=======================================================================
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!
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MODULE MATERIAL_PROPERTIES
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!
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USE ACCURACY_REAL
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!
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CONTAINS
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!
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!
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!=======================================================================
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!
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SUBROUTINE CHARACTERISTIC_LENGTHS(DMN,RS,T,B,DC,TP)
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!
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! This subroutine computes and prints out characteristic lengths
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! in the input material
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!
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! References: (1) H. van Houten, B. J. van Wees and C.W.J. Beenakker
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! in "Physics and Technology of Submicron Structures",
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! H. Heinrich, G. Bauer and F. Kuchar eds.,
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! Springer Series in Solid State Science Vol. 83,
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! pp. 198-207 (1988)
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!
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!
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! Input parameters:
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!
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! * DMN : dimension
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! * RS : Wigner-Seitz radius (in units of a_0)
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! * T : system temperature in SI
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! * B : magnetic field in SI
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! * DC : diffusion coefficient
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! * TP : phase-breaking relaxation time in SI
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!
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!
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! Author : D. Sébilleau
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!
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! Last modified : 24 Jul 2020
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!
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!
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USE REAL_NUMBERS, ONLY : ZERO,ONE,TWO,TTINY
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USE CONSTANTS_P1, ONLY : H_BAR,E,K_B
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USE FERMI_SI, ONLY : KF_SI,VF_SI
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USE PI_ETC, ONLY : PI
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USE UTILITIES_1, ONLY : D
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USE SCREENING_VEC
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!
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USE MATERIAL_CL
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!
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IMPLICIT NONE
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!
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CHARACTER (LEN = 2) :: DMN
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!
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REAL (WP) :: RS,T,B,DC,TP
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REAL (WP) :: KD,K_TF
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!
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INTEGER :: LOGF
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!
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IF(B == ZERO) B = TTINY !
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!
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EMFP=D(DMN)*DC/VF_SI ! elastic MFP
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FWL=TWO*PI/KF_SI ! Fermi wavelength
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PCL=DSQRT(DC*TP) ! phase coherence length
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THL=DSQRT(H_BAR*DC/(K_B*T)) ! thermal length
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ML=DSQRT(H_BAR/(E*B)) ! magnetic length
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CR=H_BAR*KF_SI/(E*B) ! cyclotron radius
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!
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CALL DEBYE_VECTOR(DMN,T,RS,KD) !
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DL=ONE/KD ! Debye length
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!
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CALL THOMAS_FERMI_VECTOR(DMN,K_TF) !
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TFL=ONE/K_TF ! Thomas-Fermi length
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!
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END SUBROUTINE CHARACTERISTIC_LENGTHS
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!
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END MODULE MATERIAL_PROPERTIES
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