69 |
|
($E_{\text{bath}}+E_{\gamma}$) remain constant. $\Omega(E)$, where $E$ |
70 |
|
is the total energy of both systems, can be represented as |
71 |
|
\begin{equation} |
72 |
< |
\Omega(E) = \Omega(E_{\gamma}) \times \Omega(E - E_{\gamma}) |
72 |
> |
\Omega(E) = \Omega(E_{\gamma}) \times \Omega(E - E_{\gamma}). |
73 |
|
\label{introEq:SM1} |
74 |
|
\end{equation} |
75 |
|
Or additively as |
76 |
|
\begin{equation} |
77 |
< |
\ln \Omega(E) = \ln \Omega(E_{\gamma}) + \ln \Omega(E - E_{\gamma}) |
77 |
> |
\ln \Omega(E) = \ln \Omega(E_{\gamma}) + \ln \Omega(E - E_{\gamma}). |
78 |
|
\label{introEq:SM2} |
79 |
|
\end{equation} |
80 |
|
|
86 |
|
\frac{\partial \ln \Omega(E_{\gamma})}{\partial E_{\gamma}} |
87 |
|
+ |
88 |
|
\frac{\partial \ln \Omega(E_{\text{bath}})}{\partial E_{\text{bath}}} |
89 |
< |
\frac{\partial E_{\text{bath}}}{\partial E_{\gamma}} |
89 |
> |
\frac{\partial E_{\text{bath}}}{\partial E_{\gamma}}, |
90 |
|
\label{introEq:SM3} |
91 |
|
\end{equation} |
92 |
< |
Where $E_{\text{bath}}$ is $E-E_{\gamma}$, and |
92 |
> |
where $E_{\text{bath}}$ is $E-E_{\gamma}$, and |
93 |
|
$\frac{\partial E_{\text{bath}}}{\partial E_{\gamma}}$ is |
94 |
|
$-1$. Eq.~\ref{introEq:SM3} becomes |
95 |
|
\begin{equation} |
96 |
|
\frac{\partial \ln \Omega(E_{\gamma})}{\partial E_{\gamma}} = |
97 |
< |
\frac{\partial \ln \Omega(E_{\text{bath}})}{\partial E_{\text{bath}}} |
97 |
> |
\frac{\partial \ln \Omega(E_{\text{bath}})}{\partial E_{\text{bath}}}. |
98 |
|
\label{introEq:SM4} |
99 |
|
\end{equation} |
100 |
|
|
105 |
|
process is the partitioning of energy among the two systems. This |
106 |
|
allows the following definition of entropy: |
107 |
|
\begin{equation} |
108 |
< |
S = k_B \ln \Omega(E) |
108 |
> |
S = k_B \ln \Omega(E), |
109 |
|
\label{introEq:SM5} |
110 |
|
\end{equation} |
111 |
< |
Where $k_B$ is the Boltzmann constant. Having defined entropy, one can |
112 |
< |
also define the temperature of the system using the Maxwell relation |
111 |
> |
where $k_B$ is the Boltzmann constant. Having defined entropy, one can |
112 |
> |
also define the temperature of the system using the Maxwell relation, |
113 |
|
\begin{equation} |
114 |
< |
\frac{1}{T} = \biggl ( \frac{\partial S}{\partial E} \biggr )_{N,V} |
114 |
> |
\frac{1}{T} = \biggl ( \frac{\partial S}{\partial E} \biggr )_{N,V}. |
115 |
|
\label{introEq:SM6} |
116 |
|
\end{equation} |
117 |
|
The temperature in the system $\gamma$ is then |
118 |
|
\begin{equation} |
119 |
|
\beta( E_{\gamma} ) = \frac{1}{k_B T} = |
120 |
< |
\frac{\partial \ln \Omega(E_{\gamma})}{\partial E_{\gamma}} |
120 |
> |
\frac{\partial \ln \Omega(E_{\gamma})}{\partial E_{\gamma}}. |
121 |
|
\label{introEq:SM7} |
122 |
|
\end{equation} |
123 |
|
Applying this to Eq.~\ref{introEq:SM4} gives the following |
124 |
|
\begin{equation} |
125 |
< |
\beta( E_{\gamma} ) = \beta( E_{\text{bath}} ) |
125 |
> |
\beta( E_{\gamma} ) = \beta( E_{\text{bath}} ). |
126 |
|
\label{introEq:SM8} |
127 |
|
\end{equation} |
128 |
|
Eq.~\ref{introEq:SM8} shows that the partitioning of energy between |
140 |
|
to the total energy of both systems and the fluctuations in |
141 |
|
$E_{\gamma}$: |
142 |
|
\begin{equation} |
143 |
< |
\Omega( E_{\gamma} ) = \Omega( E - E_{\gamma} ) |
143 |
> |
\Omega( E_{\gamma} ) = \Omega( E - E_{\gamma} ). |
144 |
|
\label{introEq:SM9} |
145 |
|
\end{equation} |
146 |
|
As for the expectation value, it can be defined |
147 |
|
\begin{equation} |
148 |
|
\langle A \rangle = |
149 |
|
\int\limits_{\boldsymbol{\Gamma}} d\boldsymbol{\Gamma} |
150 |
< |
P_{\gamma} A(\boldsymbol{\Gamma}) |
150 |
> |
P_{\gamma} A(\boldsymbol{\Gamma}), |
151 |
|
\label{introEq:SM10} |
152 |
|
\end{equation} |
153 |
< |
Where $\int\limits_{\boldsymbol{\Gamma}} d\boldsymbol{\Gamma}$ denotes |
153 |
> |
where $\int\limits_{\boldsymbol{\Gamma}} d\boldsymbol{\Gamma}$ denotes |
154 |
|
an integration over all accessible points in phase space, $P_{\gamma}$ |
155 |
|
is the probability of being in a given phase state and |
156 |
|
$A(\boldsymbol{\Gamma})$ is an observable that is a function of the |