

Welcome to the webpage of the Computational Physics lab. The course consists of a set of programming exercises, mostly drawn from typical problems you come across in physics. The programs have to be written in C (which you are expected to learn by yourself). The reports for each of the exercises are to be submitted as a PDF document written using latex2e (which, again, will not be taught). The set of exercises and some help pages are given below:
Help with Linux, Latex, C and gnuplot
PS: The report template above is actually a .tex file masquerading as a .pdf file.
Change file name from sc11Bxxx.pdf to sc11Bxxx.tex after downloading.
Content, and other information, such as lecture notes (including a couple of old ones), assignments, schedule, etc., for courses I offer(ed) can be found here.
Current: Physics2 (PH121), JanJune 2019
This is a course on Electricity and Magnetism, in its local form, leading to Electrodynamics. The course starts with an introduction of Differential and Integral Calculus, and ends with a summary of Maxwell's equations.
Syllabus
Assignment 1: Due  11 February
Some earlier Question papers
From 2017: Quiz 1, Quiz 2, EndSem
A few other lecture notes:
1.Relativity
2.Computational Physics
3.Quantum Mechanics (partial)
My primary interests are in Theory of Solitons, Geometry and Integrable systems with applications in Condensed Matter Physics, especially in classical spin systems, falling under the broader area of Nonlinear Dynamics. Our interest is largely around studying spin behavior in Nanoscale Ferromagnets in the context of spin transfer torque induced spin reversal, with application in magnetic recording media.
Recently we discovered knot soliton solution to the Nonlinear Schrödinger equation (NLSE). The NLSE arises a good approximation in various physical systems: describing the propogation of light in nonlinear media, vortex filament motion in inviscid fluids, evolution of a ferromagnetic spin chain, to name a few. Under certain approximations it can also describe the wave function of a Bose Einstein condensate. There exists a clear and exact mapping of the complex field satisfying NLSE to a moving curve in 3D. Within fairly good limits this curve imitates the motion of a thin vortex filament in fluids or superfluids. We have recently obtained a breather soliton solution to the NLSE, whose corresponding curve in 3D carries a knot. See 4. below for details.
As of now, we are unable to give a clear physical interpretation for the knot  it can't be thought of as a vortex filament, as it exceeds the limits of approximations where NLSE is a good description. A possible interpretation in light propogation in nonlinear media is explored.
The breather mode in a ferromagnetic spin chain carries in it an interesting topological connection. Suppose a finite spin chain in 1D is constrained with periodic boundary conditions  the ends can then be identified, or closed (as in figure below). Then, the breather mode on such a chain witnesses an evolution which continuously changes the twist in the chain from n > n2 > n, (or, a 4π change in twist, and back) a manouevre known in various popular names  the Dirac string trick, the belt trick, Balinese plate trick, etc. The curious aspect about the trick is that by a continous transformation, the total twist can only be changed by 4π, not 2π. The trick is usually used as an illustration of the simple connectedness of the group SU(2), and its period 4π.
‘Coherent Structures and Patterns in Nonlinear Systems,’ Funded by DST, GOI, under the SERC – FASTTRACK scheme (completed in 2009).