@@ -38,8 +38,8 @@ From the adibatic theorem, we know that the system will remain in the $n-th$ eig
...
@@ -38,8 +38,8 @@ From the adibatic theorem, we know that the system will remain in the $n-th$ eig
Consider a two level system described by the Hamiltonian,
Consider a two level system described by the Hamiltonian,
$$
$$
H(t) = \left( \begin{array}{cc}
H(t) = \left( \begin{array}{cc}
vt & \Delta \\
vt/2 & \Delta \\
\Delta & -vt
\Delta & -vt/2
\end{array}
\end{array}
\right).
\right).
$$
$$
...
@@ -50,7 +50,7 @@ $$
...
@@ -50,7 +50,7 @@ $$
Landau and Zaner found an explicit expression that describes the probability of tuneling to a high energy state as $t\rightarrow \infty$. It is
Landau and Zaner found an explicit expression that describes the probability of tuneling to a high energy state as $t\rightarrow \infty$. It is
$$
$$
P \sim e^{-\frac{\pi}{2v h}\frac{\Delta}{E_0-E_1}}.
P \sim e^{-2\pi\frac{|Delta|^2}{\hbar |v|}}.
$$
$$
Here, $\Delta = \langle 0 | H |1 \rangle$, and $v=d(E_0(t)-E_1(t))/dt$. From the adiabatic theorem, we recall that when the system evolves in an adiabatic way, it will remain in the initial eigenstate as shown in the animation below.
Here, $\Delta = \langle 0 | H |1 \rangle$, and $v=d(E_0(t)-E_1(t))/dt$. From the adiabatic theorem, we recall that when the system evolves in an adiabatic way, it will remain in the initial eigenstate as shown in the animation below.