Time-evolution of wavepackets as a means to bridge quantum and classical concepts

CHED 1768

Garth J Simpson, gsimpson@purdue.edu, Purdue University, 560 Oval Drive, West Lafayette, IN 47907
Static images in textbooks generally fail to capture the intrinsic dynamics underlying quantum mechanics. For example, the “stationary state” wavefunctions are anything but stationary! Simple approaches are described for including the inherent dynamic wave-nature of the time-dependent eigenstates in the introductory quantum mechanics curriculum. A few straightforward computational tools can be used to aid in visually understanding a diverse array of phenomena, including 1) interpreting angular momentum by the time-evolution of the wavefunctions, 2) watching the time-dependent evolution of the wavefunctions during the absorption or emission of a photon for atomic, vibrational, and rotational transitions, and 3) seeing recovery of classical-like motion for “particles” in boxes from linear combinations of the eigenstates (i.e., the correspondence principle expressed in the time-domain within the context of wavepackets). Assessment of the pedagogical merits of these methods will be presented.