At the top of the applet you will see a graph of the potential, along with horizontal lines showing the energy levels. By default it is an infinite square well (zero everywhere inside, infinite at the edges). Below that you will see the probability distribution of the particle's position, oscillating back and forth in a combination of two states. Below the particle's position you will see a graph of its momentum. At the bottom of the screen is a set of phasors showing the magnitude and phase of the lower-energy states.
To view a state, move the mouse over its energy level on the potential graph. To select a single state, click on it.
You may also select a single state by picking one of the phasors at the bottom and double-clicking on it. Or, you may click on the phasor and drag its value to modify the magnitude and phase. In this way, you can create a combination of states.
You may select a different potential from the Setup menu at the top right.
Hydrogen Atom Applet.
1-D Quantum Crystal Applet.
2-D Square Well Applet.
Quantum Transitions Applet.