some updates on the figures and add gibbs bound to otto

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Valentin Boettcher 2022-08-31 16:24:51 +02:00
parent eeb37cde97
commit 50050a8971
5 changed files with 19 additions and 8 deletions

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@ -1107,10 +1107,10 @@ simplifies the situation.
To further answer whether a substantial fraction of the maximal
ergotropy can be extracted from a system we have numerically optimized
the coupling strengths of the model \cref{eq:one_qubit_model_driven},
so that after three modulation periods \(τ_{m} = \frac{2 π}{Δ}\) the
so that over ten modulation periods \(τ_{m} = \frac{2 π}{Δ}\) the
maximal absolute interaction energy is close to a give value (here
\(\ev{H_{\inter}}\approx 0.4\) which constitutes quite a strong coupling) for various cutoff
frequencies \(ω_{c}\).
\(\ev{H_{\inter}}\approx 0.4\) which constitutes quite a strong
coupling) for various cutoff frequencies \(ω_{c}\).
\begin{figure}[h]
\centering
\includegraphics{figs/one_bath_mod/omega_interactions}
@ -1121,6 +1121,10 @@ frequencies \(ω_{c}\).
the parameters in \cref{tab:plus_omega}.}
\end{figure}
The resulting couplings can be found in
\cref{fig:omega_couplings_and_energies}. They correspond roughly to
demanding \(α_{β}(0)=1.4\), where \(α_{β}\) is the finite temperature
bath correlation function.
\Cref{fig:omega_couplings_and_energies} also shows that for the
simulations with small \(ω_{c}\) the positive parts of the interaction
energy are especially large.
@ -1152,14 +1156,14 @@ minimal total energy is achieved earlier and is of greater
magnitude. Further, we see that a non-trivial amount of energy is
being extracted relative to ergotropy bound \cref{eq:ergo_mod_model}.
\begin{wrapfigure}[12]{o}{.5\textwidth}
\begin{figure}
\centering
\includegraphics{figs/one_bath_mod/omega_energies_and_powers}
\caption{\label{fig:omegas_energies_and_powers} One shot power
(blue) and maximal extracted energy (orange) as a function of
the bath memory. The grey vertical line marks one
modulation period.}
\end{wrapfigure}
\end{figure}
In \cref{fig:omegas_energies_and_powers} we can see that longer
bath\fixme{looks like ``phase transition'' but really isn't} memories,
defined as the time point at which \(α(τ_{\bath}) = α(0)/10\), lead to
@ -1177,9 +1181,6 @@ is due to the requirement that power and extracted energy have to be
finite, and the stroboscopic time view induced by the requirement that
the interaction energy should be zero.
Note also, that for the two longest bath memories, the relative gain
in extracted energy is much smaller than the relative gain in power.
In conclusion we can say that in the cases studied here we can extract
a finite amount of energy from the system as soon as the bath memory
is somewhat longer than the modulation period. This statement depends
@ -1423,6 +1424,16 @@ steady state, the system and interaction related quantities are
constant in the stroboscopic view (the dots in \cref{fig:ottoenergy}),
while the total energy and the bath energies depend linearly on time.
The Gibbs like inequality \cref{eq:secondlaw_cyclic} derived in
\cref{sec:operational_thermo} can also be verified in this case.
We find
\begin{equation}
\label{eq:secondlaw_otto_actual}
__i ΔE_{\bath^i}^\cyc = 0.1096\pm 0.0008 ≥ 0,
\end{equation}
which does satisfy the inequality to over 100 standard
deviations. Minimizing this quantity would maximize the efficiency.
A worthwhile task for future work would be to verify the results
summarized in \cite{Binder2018} for the Otto cycle. Especially the
optimization for optimal power which leads to the