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pkirwin 2021-03-05 23:48:50 -07:00
parent a09d982b30
commit c67f5ff72d
5 changed files with 26 additions and 17 deletions

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@ -581,8 +581,6 @@ axis([0 1e-9 0 0.04]);
\item %3biv \item %3biv
\( sinc \) is a purely real function, so we can ignore the normalizing portion of the integral. \( sinc \) is a purely real function, so we can ignore the normalizing portion of the integral.
% TODO just replace these in the formulas themselves
As well, to simplify the interim equations we will assign the constants \( A = \frac{1}{2} \sqrt{\frac{L}{\pi \hbar}} \) As well, to simplify the interim equations we will assign the constants \( A = \frac{1}{2} \sqrt{\frac{L}{\pi \hbar}} \)
and \( B = \frac{L}{2 \pi \hbar} \). and \( B = \frac{L}{2 \pi \hbar} \).
@ -590,13 +588,14 @@ axis([0 1e-9 0 0.04]);
\int _{-\infty} ^{\infty} \Phi (p')^2 dp = \int _{-\infty} ^{\infty} A^2 \left[ sinc\left( B(p'+p_1) \right)^2 + 2 sinc \left( B(p'+p_1) \right) sinc \left( B(p'-p_1) \right) + sinc \left( B(p'-p_1) \right) \right] dp \int _{-\infty} ^{\infty} \Phi (p')^2 dp = \int _{-\infty} ^{\infty} A^2 \left[ sinc\left( B(p'+p_1) \right)^2 + 2 sinc \left( B(p'+p_1) \right) sinc \left( B(p'-p_1) \right) + sinc \left( B(p'-p_1) \right) \right] dp
\end{equation*} \end{equation*}
Given property (26) of the \( sinc \) function, we can simplify the left and right elements. % TODO better word than elements Given property (26) of the \( sinc \) function, we can simplify the left and right terms.
Using a change of variable \( p'' = p_1 - p' \), and properties (27) and (28), we can further evaluate the central element. Using a change of variable \( p'' = p_1 - p' \), and properties (27) and (28), we can further evaluate the central term.
\begin{align} \begin{align}
\int _{-\infty} ^{\infty} \Phi (p')^2 dp = \int _{-\infty} ^{\infty} A^2 \left[2 sinc \left( B(2p_1 - p'') \right) sinc \left( B(-p'') \right) \right] dp + A^2 \frac{2}{B} \\ \int _{-\infty} ^{\infty} \Phi (p')^2 dp = \int _{-\infty} ^{\infty} A^2 \left[2 sinc \left( B(2p_1 - p'') \right) sinc \left( B(-p'') \right) \right] dp + A^2 \frac{2}{B} \\
&= \int _{-\infty} ^{\infty} A^2 \left[ 2 sinc \left(B(2p_1 - p'') \right) sinc(B p'') \right] dp + A^2 \frac{2}{B} \\ &= \int _{-\infty} ^{\infty} A^2 \left[ 2 sinc \left(B(2p_1 - p'') \right) sinc(B p'') \right] dp + A^2 \frac{2}{B} \\
&= \frac{A^2}{B} \left[ sinc(2p_1) + 2 \right] \\ &= \frac{A^2}{B} \left[ sinc(2p_1) + 2 \right] \\
&= \frac{1}{2} \left[ sinc(2p_1) + 2 \right]
\end{align} \end{align}
\item %3bv \item %3bv
@ -679,36 +678,47 @@ axis([0 1e-9 0 0.04]);
\begin{enumerate}[align=left,leftmargin=*,labelsep=1em,label=\bfseries(\alph*)] \begin{enumerate}[align=left,leftmargin=*,labelsep=1em,label=\bfseries(\alph*)]
\item %4a \item %4a
\begin{minipage}[t]{\linewidth}
\begin{figure}[H] \begin{figure}[H]
\centering \centering
\begin{subfigure}{0.5\textwidth} \begin{subfigure}[b]{0.5\textwidth}
\centering \centering
\includegraphics[width=\textwidth]{q4a_e1.png} \includegraphics[width=\textwidth]{q4a_e1.png}
\caption{} \caption{}
\end{subfigure}% \end{subfigure}%
\begin{subfigure}{0.5\textwidth} \begin{subfigure}[b]{0.5\textwidth}
\centering \centering
\includegraphics[width=\textwidth]{q.png} \includegraphics[width=\textwidth]{q4a_e2.png}
\caption{} \caption{}
\end{subfigure} \end{subfigure}
\caption{(a),(b) Previous plots but with the classical momentum marked in red.} \caption{Probability Density Plots for first two energy levels.}
\end{figure} \end{figure}
\end{minipage}
% TODO I really don't like this explanation...
An \( a \) value of \( 0.53 \angstrom \) was chosen in order to provide an adequately An \( a \) value of \( 0.53 \angstrom \) was chosen in order to provide an adequately
shaped graph without sacrificing too much computation time and ensure that the first two shaped graph without sacrificing too much computation time and ensure that the first two
numerical energies correspond to the given experimental results. The experimental results are numerical energies correspond to the given experimental results. The experimental results are
\(\SI{0.14395}{\electronvolt}\) and \(\SI{0.43185}{\electronvolt} \) for the first and second energy levels \(\SI{0.14395}{\electronvolt}\) and \(\SI{0.43185}{\electronvolt} \) for the first and second energy levels
respectively, and the numerical results with our chosen \(a\) are \(\SI{0.0.14386}{\electronvolt}\) and \(\SI{0.43140}{\electronvolt} \) respectively, and the numerical results with our chosen \(a\) are \(\SI{0.14386}{\electronvolt}\) and \(\SI{0.43140}{\electronvolt} \),
which are in agreement.
% maybe talk about normalization?
\item %4b \item %4b
\begin{enumerate}[align=left,leftmargin=*,labelsep=0em,label=(\roman*)] \begin{enumerate}[align=left,leftmargin=*,labelsep=0em,label=(\roman*)]
\item %4bi \item %4bi
\lipsum[1]
The energies were used were \( 0.14395eV \) and \( 0.43185eV \) for the first and second energy levels,
respectively.
\begin{minipage}[H]{\linewidth}
\centering
\includegraphics[width=\textwidth]{q4bi_I-V.png}
\captionof{figure}{Current vs. Voltage.}
\end{minipage}
\item %4bii \item %4bii
Between \( 0V \) and \( 0.25V \), only the first energy level is carrying any current. Between \( 0V \) and \( 0.25V \), only the first energy level is carrying any current.
@ -716,14 +726,13 @@ axis([0 1e-9 0 0.04]);
energy level drops to 0, meaning no electrons can transfer. energy level drops to 0, meaning no electrons can transfer.
Between \(0.4V\) and \(0.65V\), only the second energy level is carrying current. Between \(0.4V\) and \(0.65V\), only the second energy level is carrying current.
This energy level stops dropping current because it's shifted energy drops below This energy level stops conducting current because it's shifted energy drops below
the threshold where the contacts have any coupling with it. the threshold where the contacts have any coupling with it.
\item %4biii \item %4biii
Negative Drain Resistance (NDR) is present in this design from a \(V_D\) of Negative Drain Resistance (NDR) is present in this design from a \(V_D\) of
approximately \(0.27V\) to \(0.45V\), with a mostly linear region from approximately \(0.27V\) to \(0.45V\), as well as from \(0.65V\) to \(0.8V\)
aroung \(0.28V\) to \(0.3V\).
\end{enumerate} \end{enumerate}

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@ -19,7 +19,7 @@ U0 = 0.025;
kBT = 0.025; kBT = 0.025;
mu = 0; mu = 0;
cal_E1 = 0.2879 / 2; cal_E1 = 0.2879 / 2;
cal_E2 = 0.2879 * 3 / 2; cal_E2 = 0.2879 * 3 / 2 - 0.1;
% Capacitance parameters % Capacitance parameters

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