Articles written in Resonance – Journal of Science Education
Volume 11 Issue 1 January 2006 pp 63-78 General Article
Volume 15 Issue 5 May 2010 pp 428-433 General Article
Volume 23 Issue 1 January 2018 pp 41-55 General Article
We revisit the Saha Ionization Equation in order to highlightthe rich interdisciplinary content of the equation thatstraddles distinct areas of spectroscopy, thermodynamics andchemical reactions. In a self-contained discussion, relegatedto an appendix, we delve further into the hidden message ofthe equation in terms of rate theory. We empoly a pedagogicalstyle appropriate for a course in equilibrium and nonequilibriumstatistical mechanics.
Volume 23 Issue 9 September 2018 pp 949-963 General Article
In this article, we discuss how a combination of electrodynamicsand quantum mechanics makes interference measurementsof the quantum phase possible in terms of the vectorpotential, neither of which is detectable independently. Thiseffect, predicted by Aharonov and Bohm, is of great significancein the contemporary interesting topic of nanoscopicphysics. We also indicate how the effect can be incorporatedin a solid state device by employing the tight-binding (TB)model. The TB model can be realized in a mesoscopic ringwhich allows the measurement of the bond current and theassociated diamagnetism. An exactly solvable case of a threesitering is presented that serves as a pedagogic example providingfurther insights into the phenomenon.
Volume 25 Issue 8 August 2020 pp 1117-1125 General Article
We present here an overview of Late P. W. Anderson’s doc-toral thesis on Spectral Line shapes in the backdrop of his very intimate relation with the physics community of Japan—in particular, R. Kubo.
Volume 26 Issue 8 August 2021 pp 1103-1123 General Article
Standard thermodynamics pertains to a system in equilibrium. The meaning of equilibrium is that all fields such as temperature, pressure, magnetic, electric fields, etc., are held fixed, and the system is allowed sufficient time so that all dynamical variables, e.g., position, momentum, and their functions, remain constant in time, on the average. If any of the aforesaid fields is changed to another value, the system, in general, is expected to come to a new equilibrium after a time much longer than what is known as the 'relaxation time'. Standard thermodynamics, however, does not touch upon the issue of the relaxation time or the time-evolution of the system. In recent years, there has been an upsurge of interest in nanoscience, especially in the context of biology and materials, wherein the systems of interest are so tiny that they are hardly ever in equilibrium. Therefore, there is a need to go beyond standard thermodynamics and treat fluctuating, time-dependent effects. Stochastic Thermodynamics is one such important development that is pedagogically reviewed in this article. Our treatment will be restricted to classical systems.
Volume 26 Issue 12 December 2021 pp 1677-1703 General Article
Two-level quantum systems have their ubiquitous presence in chemistry and physics---in the basic ideas of bonding of atoms based on the superposition of two quantum states; in quantum optics and laser physics; in magnetic resonance; and a multitude of other phenomena. The underlying theory is well-described in many textbooks. This article aims to go beyond textbooks and familiarize university students (and hopefully excite them) about several related topics of great contemporary interest in chemistry and physics of materials, remaining however within their accessible realm. These topics are of current research activity, including tunneling centers in solids, coherent preservation of quantum information in qubits, hybridization of orbitals in carbon leading to materials such as graphene, the Berry phase, and its implication for magnetic monopoles, topological solids, and Rashba spin-split bands, etc. In discussing these themes, references are made to textbooks of quantum mechanics, but the connection is provided to advanced areas in a manner that is pedagogical and not forbidding to students.
Volume 27 Issue 4 April 2022 pp 543-559 General Article
We investigate here electron transport in a tight-binding chain under the action of a time-dependent force field. From the exact results for the mean-squared displacement, we discuss various special cases of zero field, static field, and oscillatory field. The consequent delocalization and localization phenomena make the tight-binding chain a textbook example for studying quantum coherent motion.
Volume 27 | Issue 8