This book explores interesting possibilities of extracting information about quantum states from data readily obtained from experiments, such as tomograms and expectation values of appropriate observables. The procedures suggested for identifying nonclassical effects such as wave packet revivals, squeezing and entanglement solely from tomograms circumvent detailed state reconstruction. Several bipartite entanglement indicators are defined based on tomograms, and their efficacy assessed in models of atom-field interactions and qubit systems. Tools of classical ergodic theory such as time series and network analysis are applied to quantum observables treated as dynamical variables. This brings out novel aspects involving different time scales. The book is aimed at researchers in the areas of quantum optics and quantum dynamics.

S. Lakshmibala earned her Ph. D. degree in theoretical high energy physics from the University of Madras in 1987 and joined the Department of Physics, IIT Madras, as a postdoctoral fellow. She became a faculty member in 1991 and is currently a professor there. Her research has ranged over particle physics, nonlinear dynamics, and the interface between quantum mechanics and quantum optics. For the past two decades, her research has focused on the general theme of the ergodic properties of the expectation values of observables in quantum mechanical systems, particularly in the context of paradigmatic atom-field interaction models in quantum optics. In addition to significant work in this area, she has also pioneered the application of time series and network analysis to quantum dynamics. She has taught a variety of courses at the undergraduate and graduate levels and has also given an NPTEL-sponsored video course on quantum mechanics (available on YouTube) that has been very well received. Among her current research interests is the tomographic approach to the exploration of entanglement in bipartite and multipartite systems.

V. Balakrishnan earned his Ph. D. degree in theoretical high energy physics from Brandeis University in 1970. After a decade of research at TIFR (Mumbai) and IGCAR (Kalpakkam), he joined IIT Madras in 1980 as a professor, retired as professor emeritus in 2013, and is currently an adjunct professor there. His research interests have spanned many areas over the years, including particle physics, mechanical behavior of solids, condensed matter physics, random walks and stochastic processes, nonlinear dynamics and chaos, and quantum dynamics, in which he has published numerous research papers and articles. He has made significant contributions to the theory of an elasticity and viscoelasticity, anomalous diffusion and continuous time random walks, first-passage times for random walks on fractals, and extreme-value and recurrence-time distributions in chaotic dynamics. He is a co-author of Beyond the Crystalline State (Springer, 1989) and the author of Elements of Nonequilibrium Statistical Mechanics (Ane Books, 2008; Springer, 2021), Mathematical Physics (Ane Books, 2018; Springer, 2020) and A Miscellany of Mathematical Physics (Indian Academy of Sciences, 2018). Over four decades, he has taught a wide variety of extremely popular courses at the undergraduate and graduate levels. He has given seven NPTEL-sponsored video courses (available on YouTube). These have received very high acclaim, with a total of several million views worldwide. He has been a fellow of the Indian Academy of Sciences since 1985.