From 54de11b2abca604103c5a3cf8b8d40ee6ddec7f7 Mon Sep 17 00:00:00 2001
From: e3fm8 <wolf.widdra@physik.uni-halle.de>
Date: Tue, 27 Feb 2024 18:06:45 +0100
Subject: [PATCH] added plasmaFrequencySTO
---
libhreels/dielectrics20.py | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/libhreels/dielectrics20.py b/libhreels/dielectrics20.py
index f3e6b60..584fd8c 100755
--- a/libhreels/dielectrics20.py
+++ b/libhreels/dielectrics20.py
@@ -4,18 +4,18 @@ import numpy as np
from scipy import constants
from scipy.integrate import cumulative_trapezoid
-def plasmaFrequency(n,eps_inf=1):
- '''Returns the plasma frequency for a given doping n in charge/m³.'''
- # Note that the function parameter is actually n/m, the charge carrier density
- # over the band mass in units of electron mass in vacuum.
+def plasmaFrequency(n,eps_inf=1, m=1):
+ # Returns the plasma frequency in cm^-1 for a given charge carrier density n in e/m³
+ # and a polarisable medium described by eps_infinity
+ # and a band mass m in units of electron mass in vacuum.
eps_0 = constants.value("vacuum electric permittivity")
e = constants.value('elementary charge')
m_e = constants.value('electron mass')
# Careful: There is a factor of 2 pi between omega and nue:
# If the plasma oscillates in a polarisable medium eps_infinity will reduce the restoring fields
- w_P = np.sqrt(n*e*e/(eps_0*eps_inf*m_e)) #
+ w_P = np.sqrt(n*e*e/(eps_0*eps_inf*m_e*m)) #
nue_P = w_P /1E+12 * 33.35641 /2 /np.pi #Hz -> THz -> cm^-1
- return nue_P
+ return nue_P # in units of cm-1
def chargeDensitySTO(x):
# Calculates the charge density per m^3 for SrTi_(1-x)Nb_xO_3
@@ -23,6 +23,13 @@ def chargeDensitySTO(x):
vol = 3.91*3.91*3.91 * 1E-30 # unit cell volume in m^3
return x/vol
+def plasmaFrequencySTO(x,eps_inf=5.14,m=15):
+ # Calculates the plasma frequency in cm^-1 for SrTi_(1-x)Nb_xO_3
+ # assuming doping by one electron per Nb atom
+ # and an effective mass m=15
+ vol = 3.91*3.91*3.91 * 1E-30 # unit cell volume in m^3
+ return plasmaFrequency(x/vol,eps_inf, m=m)
+
def loss(eps):
'''Returns the loss function for a given eps'''
--
GitLab