Time-Dependent Superposition of 2D Particle-in-a-Box Eigenstates

This Demonstration looks at a time-dependent superposition of quantum particle-in-a-box eigenstates in two dimensions (a square box in this example), , where the eigenfunctions and eigenvalues are given by and , respectively. The index of summation ranges over combinations of and that correspond to the lowest six energy levels. The top graphic shows the 2D probability density , and the lower graphics show the position expectation values and .