deletions | additions       diff --git a/When_applied_an_electric_field__.tex b/When_applied_an_electric_field__.tex  index 58fd6b8..791cd7d 100644  --- a/When_applied_an_electric_field__.tex  +++ b/When_applied_an_electric_field__.tex 
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\begin{equation}  \sigma(E) = \sigma_a + \sigma_b exp(-E_0/E)  \end{equation} CDW was modeled as a classical particle moving in a "wash board" potential, which was approximated by parabolic and sinusoidal potentials. Only when the applied electric field exceeds some threshold value $E_th$ will the CDW "particle" start to "slide". This is also known as the "depinning" process of CDW \cite{Gr_ner_1981}. The conductance in this case is "diode-like".