}
@Article{parcas_md,
- title = "{PARCAS} molecular dynamics code",
+ journal = "{PARCAS} molecular dynamics code",
author = "K. Nordlund",
year = "2008",
}
title = "The Fitting of Pseudopotentials to Experimental Data
and Their Subsequent Application",
editor = "Frederick Seitz Henry Ehrenreich and David Turnbull",
- booktitle = "",
publisher = "Academic Press",
year = "1970",
volume = "24",
\definecolor{linkcolour}{rgb}{0,0.2,0.6}
\hypersetup{colorlinks,breaklinks, urlcolor=linkcolour, linkcolor=linkcolour}
-\Absender{\small Frank Zirkelbach, Vorderer Lech 49, 86150 Augsburg, Germany\\}
+\Absender{\small Frank Zirkelbach, R\"omerweg 10, 86391 Stadtbergen, Germany\\}
\phone{0821}{436915}
\opening{Dear Dr. Bester,}
-I am writing to apply for the postdoctoral position in the area of dynamical processes at the nanoscale as advertized in the online presence of the Max Planck Institute for Solid State Research.
+I am writing to apply for the postdoctoral position in the area of dynamical processes at the nanoscale as advertised in the online presence of the Max Planck Institute for Solid State Research.
I am currently doing my doctoral studies at the Institute of Physics at the University of Augsburg.
Although the division I am working in concentrates on experimental physics, I have been given the opportunity to work on a rather theoretical field already with the beginning of my diploma thesis.
The writing of my doctoral thesis has just been completed and the studies will hopefully come to an end soon, presumably with the viva voce in mid October.
A quite extensive overview of the whole work is, for instance, given in the latest publication as specified in the attached CV.
I am highly interested in the offered research project involving methods that go beyond ground-state density functional theory.
-Modeling a self-organization process realized by the Monte-Carlo technique within the diploma thesis followed by the doctoral reaseach investigations utilizing the more sophisticated empirical potential molecular dynamics approach, which were extended by superior, highly accurate quantum-mechanical calculations, allowed to gain a considerable amount of experiences within the respective methods and the focus on structures and structural evolution on the nanoscale.
-Consequently, it is now natural to enter the field of methods that go beyond ground-state density functional theory.
-
-
-I would like to ... go beyond ...
-... and correlated systems ... dynamic correlations ...
-... to get into ... as we as the underlying theory.
+Modeling a self-organization process realized by the Monte-Carlo technique within the diploma thesis followed by the doctoral research investigations utilizing the more sophisticated empirical potential molecular dynamics approach, which were extended by superior, highly accurate quantum-mechanical calculations, allowed to gain a considerable amount of experiences within the respective methods and the focus on structures and structural evolution on the nanoscale.
+Now, I would be happy to enter the field of methods that go beyond ground-state density functional theory with respect to both, application and development, as I would be given the opportunity in your research group.
Doing computational materials science at an experimental physics division starting with the the diploma thesis, has, since then, demanded a high level of autonomy.
And still, a vivid interaction with experimental scientists was given, my supervisors being amongst them.
Please find appended my CV (including the list of publications) for your review.
For any further information, please feel free to contact me.
-I would be happy to send you the latest (not yet available) publication or the preliminary version of my thesis.
+If desired, I would be happy to send you the preliminary version of my thesis.
I would be very glad to hear from you.
\section{Personal Data}
\begin{tabular}{rl}
\textsc{Place and Date of Birth:} & Berlin, Germany | 17 November 1977\\
-\textsc{Address:} & Vorderer Lech 49, 86150 Augsburg, Germany\\
+\textsc{Address:} & R\"omerweg 10, 86391 Stadtbergen, Germany\\
\textsc{Phone:} & +49 821 598 3008 (work)\\
& +49 175 5228066 (mobile)\\
\textsc{Fax:} & +49 821 598 3425 (work)\\
\textsc{http:} & \href{http://www.physik.uni-augsburg.de/~zirkelfr}{http://www.physik.uni-augsburg.de/\textasciitilde{}zirkelfr}\\
\end{tabular}
\begin{picture}(0,0)(-15,38)
-\includegraphics[height=3.0cm]{img/frank_app_ult.eps}
-%\includegraphics[height=3.0cm]{img/frank_app_mountain.eps}
+%\includegraphics[height=3.0cm]{img/frank_app_ult.eps}
+\includegraphics[height=3.0cm]{img/frank_app_mountain.eps}
\end{picture}
\section{Work Experience}
\section{Basic education}
\begin{tabular}{r|p{11cm}}
\textsc{Sep 1988 - Jul 1998} & \textbf{Grammar school}\newline
- Justus-von-Liebig-Gymnasium, Neus\"ass\newline
+ Justus-von-Liebig-Gymnasium, Neus\"a\ss\newline
Holbein-Gymnasium, Augsburg\\
\multicolumn{2}{c}{}\\ %this clears the space between two jobs
\textsc{Sep 1984 - Jul 1988} & \textbf{Elementary school}\newline
Combined structures of C$_{\text{s}}$ and Si$_{\text{i}}$ T are energetically less favorable than the ground state C$_{\text{i}}$ \hkl<1 0 0> DB configuration.
With increasing separation distance the energies of formation decrease.
However, even for non-interacting defects, the energy of formation, which is then given by the sum of the formation energies of the separated defects (\unit[4.15]{eV}) is still higher than that of the C$_{\text{i}}$ \hkl<1 0 0> DB.
-Unexpectedly, the structure of a Si$_{\text{i}}$ \hkl<1 1 0> DB and a neighbored C$_{\text{s}}$, which is the most favored configuration of C$_{\text{s}}$ and Si$_{\text{i}}$ according to quantum-mechanical calculations\cite{zirkelbach11a}, likewise constitutes an energetically favorable configuration within the EA description, which is even preferred over the two least separated configurations of C$_{\text{s}}$ and Si$_{\text{i}}$ T.
+Unexpectedly, the structure of a Si$_{\text{i}}$ \hkl<1 1 0> DB and a neighbored C$_{\text{s}}$, which is the most favored configuration of a C$_{\text{s}}$ and Si$_{\text{i}}$ DB according to quantum-mechanical calculations\cite{zirkelbach11a}, likewise constitutes an energetically favorable configuration within the EA description, which is even preferred over the two least separated configurations of C$_{\text{s}}$ and Si$_{\text{i}}$ T.
This is attributed to an effective reduction in strain enabled by the respective combination.
Quantum-mechanical results reveal a more favorable energy of fomation for the C$_{\text{s}}$ and Si$_{\text{i}}$ T (a) configuration.
However, this configuration is unstable involving a structural transition into the C$_{\text{i}}$ \hkl<1 1 0> interstitial, thus, not maintaining the tetrahedral Si nor the substitutional C defect.
+
+Thus, the underestimated energy of formation of C$_{\text{s}}$ within the EA calculation does not pose a serious limitation in the present context.
+Since C is introduced into a perfect Si crystal and the number of particles is conserved in simulation, the creation of C$_{\text{s}}$ is accompanied by the creation of Si$_{\text{i}}$, which is energetically less favorable than the ground state, i.e. the C$_{\text{i}}$ \hkl<1 0 0> DB configuration, for both, the EA and ab initio treatment.
In either case, no configuration more favorable than the C$_{\text{i}}$ \hkl<1 0 0> DB has been found.
Thus, a proper description with respect to the relative energies of formation is assumed for the EA potential.
New accelerated methods have been developed to bypass the time scale problem retaining proper thermodynamic sampling\cite{voter97,voter97_2,voter98,sorensen2000,wu99}.
However, the applied potential comes up with an additional limitation, as previously mentioned in the introduction.
-The cut-off function of the short range potential limits the interaction to nearest neighbors, which results in overestimated and unphysical high forces between neighbored atoms.
+%The cut-off function of the short range potential limits the interaction to nearest neighbors, which results in overestimated and unphysical high forces between neighbored atoms.
+The cut-off function of the short range potential limits the interaction to nearest neighbors.
+Since the total binding energy is, thus, accommodated within this short distance, which according to the universal energy relation would usually correspond to a much larger distance, unphysical high forces between two neighbored atoms arise.
+While cohesive and formational energies are often well described, these effects increase for non-equilibrium structures and dynamics.
This behavior, as observed and discussed for the Tersoff potential\cite{tang95,mattoni2007}, is supported by the overestimated activation energies necessary for C diffusion as investigated in section \ref{subsection:cmob}.
Indeed, it is not only the strong, hard to break C-C bond inhibiting C diffusion and further rearrangements in the case of the high C concentration simulations.
This is also true for the low concentration simulations dominated by the occurrence of C$_{\text{i}}$ \hkl<1 0 0> DBs spread over the whole simulation volume, which are unable to agglomerate due to the high migration barrier.
% --------------------------------- references -------------------
-%\bibliography{../../bibdb/bibdb}{}
-%\bibliographystyle{h-physrev3}
+\bibliography{../../bibdb/bibdb}{}
+\bibliographystyle{h-physrev3}
+\ifnum1=0
\begin{thebibliography}{100}
\end{thebibliography}
+\fi
+
\end{document}
silicon carbide precipitation in silicon
by F. Zirkelbach, B. Stritzker, K. Nordlund, et al.
+and related to
+
+Re: BA11443
+ First-principles study of defects in carbon-implanted silicon
+ by F. Zirkelbach, B. Stritzker, J. K. N. Lindner, et al.
+
Dear Dr. Dahal,
The referee
- i) requests a clarification of the relation of the present
+ i) has reservations about the methodology used in the present work
+ ii) requests a clarification of the relation of the present
manuscript to a previous submission of ours (BA11443)
- ii) has reservations about the methodology used in the present work
iii) suggests to possibly combine some account of the present
work with the previous submission BA11443.
-What concerns (ii), the classical potential molecular dynamics used in
+What concerns (i), the classical potential molecular dynamics used in
the present work certainly has limitations. Precisely in order to
quantify these limitations, a comparison is made with ab initio
calculations as well as earlier first-principles work (BA11443).
accessible to more accurate ab initio techniques. A detailed response
to the referee's concerns is given below.
-Concerning (i) and (iii), the ab initio work BA11443 is a
+Concerning (ii) and (iii), the ab initio work BA11443 is a
self-contained and comprehensive manuscript, which already now has an
appreciable length. It is a first-principles study on defects in
carbon-implanted silicon. In contrast, the present study mainly
formation energies of single defects with respect to the size of the
supercell is assumed.
-A repsective statement was added (Change 3).
+A respective statement was added (Change 3).
> They appear to be separating defects by as large a distance as
> can be accommodated in the supercell to approximate the isolated
> authors aware of them? Have they used one of them?
The constrained relaxation technique is used to determine migration
-pathways. The method is named and a reference is given in the
+pathways. The method is specified and a reference is now given in the
methodology section. The method not necessarily unveils the lowest
energy migration path. The supposed saddle point structure needs to be
attested by investigating the vibrational modes. However, reasonable
> in the method do not introduce further uncertainties, and I would
> need a bit more convincing that the results are actually valid.
-We hope to be able to convince by responding to the following
-statement of the referee.
+See below for hopefully convincing arguments.
> The authors' circumvention of this is to do the simulations at
> much heightened temperatures. However, this only gives a good
> this case.
There is not necessarily a correlation of the cohesive and migration
-energies. You can always add a constant to the cohesive energies of
+energies. One can always add a constant to the cohesive energies of
respective structures. It is the difference in the cohesive energies
of structures within the migration path, which determines the
migration barrier.
\section{3C-SiC precipitate in crystalline silicon}
\label{section:const_sic:prec}
-{\color{red}Todo: Phase stability as Kai Nordlund proposed}
+{\color{red}Todo: Phase stability as Kai Nordlund proposed (120 Tm simulations).}
A spherical 3C-SiC precipitate enclosed in a c-Si surrounding is constructed as it is expected from IBS experiments and from simulations that finally succeed in simulating the precipitation event.
On the one hand this sheds light on characteristic values like the radial distribution function or the total amount of free energy for such a configuration that is aimed to be reproduced by simulation.
This is surprising since the melting transition of plain c-Si is expected at temperatures around 3125 K, as discussed in section \ref{subsection:md:tval}.
Obviously the precipitate lowers the transition point of the surrounding c-Si matrix.
This is indeed verified by visualizing the atomic data.
+% ./visualize -w 640 -h 480 -d saves/sic_prec_120Tm_cnt1 -nll -11.56 -0.56 -11.56 -fur 11.56 0.56 11.56 -c -0.2 -24.0 0.6 -L 0 0 0.2 -r 0.6 -B 0.1
\begin{figure}[!ht]
\begin{center}
\begin{minipage}{7cm}
\section*{Basic education}
\begin{tabular}{r|p{10cm}}
-\textsc{Sep 1988 - Jul 1998} & \textbf{Grammar school}\newline
+\textsc{Sep 1988 -- Jul 1998} & \textbf{Grammar school}\newline
Justus-von-Liebig-Gymnasium, Neus\"a\ss\newline
Holbein-Gymnasium, Augsburg\\
\multicolumn{2}{c}{}\\
-\textsc{Sep 1984 - Jul 1988} & \textbf{Elementary school}\newline
+\textsc{Sep 1984 -- Jul 1988} & \textbf{Elementary school}\newline
Ernst-Habermann-Grundschule, Berlin, Wilmersdorf\\
\end{tabular}
\section*{Conscription}
\begin{tabular}{r|p{10cm}}
-\textsc{Aug 1998 - Sep 1999} & \textbf{Alternative civilian service}\newline
+\textsc{Aug 1998 -- Sep 1999} & \textbf{Alternative civilian service}\newline
Hessing-Klinik, Augsburg\\
\end{tabular}
\section*{Scientific education}
\begin{tabular}{r|p{10cm}}
-\textsc{Jan 2006 - Present} & \textbf{Doctoral studies in physics}\newline
+\textsc{Jan 2006 -- Present} & \textbf{Doctoral studies in physics}\newline
Physics Department, University of Augsburg\newline {\small
\begin{tabular}{lp{8cm}}
Thesis: &
\end{tabular}
}\\
\multicolumn{2}{c}{}\\
-\textsc{Jul 2009 - Present} & \textbf{Collaboration with the University of Paderborn}\newline
+\textsc{Jul 2009 -- Present} & \textbf{Collaboration with the University of Paderborn}\newline
Theoretical Physics, Physics Department\\
\multicolumn{2}{c}{}\\
-\textsc{Jan 2006 - Dec 2008} & \textbf{Scholarship student}\newline
+\textsc{Jan 2006 -- Dec 2008} & \textbf{Scholarship student}\newline
Bayerische Forschungsstiftung\\
\multicolumn{2}{c}{}\\
\textsc{Oct/Nov 2007} & \textbf{Research period at the University of Helsinki}\\
$D_c(\epsilon)=\frac{1}{2\pi^2}(\frac{2m_n}{\hbar^2})^{3/2}(\epsilon-E_c)^{1/2}$ and
$D_v(\epsilon)=\frac{1}{2\pi^2}(\frac{2m_p}{\hbar^2})^{3/2}(E_v-\epsilon)^{1/2}$.
Simplify the Fermi function before calculating the integral and use the substitutions $x=(\epsilon - E_{\text{c}})/k_{\text{B}}T$ and $x=(E_{\text{v}}-\epsilon)/k_{\text{B}}T$.
-Furthermore use the equality $\int_0^{\infty} x^{1/2} e^{-x} dx = 1/2 \sqrt{\pi}$.
+Furthermore use the equality $\int_0^{\infty} x^{1/2} e^{-x} dx = \frac{\sqrt{\pi}}{2}$.
\end{document}
$\Rightarrow$
$n=\frac{1}{2\pi^2}(\frac{2m_nk_{\text{B}}T}{\hbar^2})^{3/2}
\exp(-\frac{E_{\text{c}}-\mu_{\text{F}}}{k_{\text{B}}T})
- \underbrace{\int_0^{\infty}x^{1/2}e^{-x}dx}_{=1/2\sqrt{\pi}}=
+ \underbrace{\int_0^{\infty}x^{1/2}e^{-x}dx}_{=\frac{\sqrt{\pi}}{2}}=
\underbrace{2(\frac{m_nk_{\text{B}}T}{2\pi\hbar^2})^{3/2}}_{=N_{\text{c}}}
\exp(-\frac{E_{\text{c}}-\mu_{\text{F}}}{k_{\text{B}}T})=
N_{\text{c}}\exp(-\frac{E_{\text{c}}-\mu_{\text{F}}}{k_{\text{B}}T})$
$\mu_{\text{F}}-\epsilon >> k_{\text{B}}T$
$\Rightarrow$
$1-f(\epsilon,T)=
- 1-\frac{1}{\exp(\frac{\mu_{\text{F}}-\epsilon}{k_{\text{B}}T})+1}\approx
+ 1-\frac{1}{\exp(\frac{\epsilon-\mu_{\text{F}}}{k_{\text{B}}T})+1}\approx
\exp(\frac{\epsilon-\mu_{\text{F}}}{k_{\text{B}}T})$\\
Parabolic approximation:
$D_v(\epsilon)=\frac{1}{2\pi^2}(\frac{2m_p}{\hbar^2})^{3/2}(E_v-\epsilon)^{1/2}$
\frac{1}{2\pi^2}(\frac{2m_p}{\hbar^2})^{3/2}
\exp(-\frac{\mu_{\text{F}}}{k_{\text{B}}T})
\int_{-\infty}^{E_{\text{v}}}(E_v-\epsilon)^{1/2}
- \exp(-\frac{\epsilon}{k_{\text{B}}T})d\epsilon$\\
+ \exp(\frac{\epsilon}{k_{\text{B}}T})d\epsilon$\\
Use: $x=(E_{\text{v}}-\epsilon)/k_{\text{B}}T$
$\Rightarrow\epsilon=E_{\text{v}}-xk_{\text{B}}T$ and
- $d\epsilon=-k_{\text{B}}Tdx$\\
+ $d\epsilon={\color{red}-}k_{\text{B}}Tdx$\\
$\Rightarrow$
$p=\frac{1}{2\pi^2}(\frac{2m_pk_{\text{B}}T}{\hbar^2})^{3/2}
\exp(\frac{E_{\text{v}}-\mu_{\text{F}}}{k_{\text{B}}T})
- \underbrace{\int_0^{\infty}x^{1/2}e^{-x}dx}_{=1/2\sqrt{\pi}}=
+ \underbrace{\int_{{\color{red}0}}^{{\color{red}\infty}}x^{1/2}e^{-x}dx}_{=\frac{\sqrt{\pi}}{2}}=
\underbrace{2(\frac{m_pk_{\text{B}}T}{2\pi\hbar^2})^{3/2}}_{=N_{\text{v}}}
\exp(\frac{E_{\text{v}}-\mu_{\text{F}}}{k_{\text{B}}T})=
N_{\text{v}}\exp(\frac{E_{\text{v}}-\mu_{\text{F}}}{k_{\text{B}}T})$
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