Superrevivals in the Quantum Dynamics of a Particle Confined in a Finite Square Well Potential

The wavepacket in quantum mechanics is often viewed as the most `nearly classical' state and is known to exhibit many striking classical properties.However, its inherent quantum nature also causes it to exhibit many quantum mechanical features.It is known that in certain nonlinear quantum systems the dynamics of the wave packet incorporates quantum interference effects which cause it to undergo a sequence of collapses and revivals and in the course of its evolution thewavepacket periodically breaks up and reconstitutes its original form.At intermediate times the wavepacket gathers into a series of subsidiary wavepackets called fractional revivals.Recently there has been a lot of interest in the theoretical and experimental study of quantum revivals in a variety of nonlinear systems like that of Rydberg atom wavepackets, molecular wavepackets, wave packets in semiconductor quantum wells etc.In this work we examine the revival features in wave packet dynamics of a particle confined in a finite square well potential.We show that the possibility of tunneling modifies the revival pattern as compared to an infinite square well potential.We study the dependence of the revival times on the depth of the square well and predict the existence of superrevivals.The nature of these superrevivals is compared with similar features seen in the dynamics of wavepackets in an anharmonic oscillator potential.