Title: Radiations, their detection and Detectors (Lecture-3)

Speaker: Prof. D. P. Mahapatra, Ex-Professor, IOP

Venue: IOP Lecture Hall

Date: 2017-Feb-28 15:30:00

Abstract:

Title: Radiations, their detection and Detectors (Lecture-4)

Speaker: Prof. D. P. Mahapatra, Ex-Professor, IOP

Venue: IOP Lecture Hall

Date: 2017-Mar-01 15:30:00

Abstract:

Title: Non-local multi-particle geometric phases in electronic intensity interferometry

Speaker: Prof. Sourin Das, IISER Kolkata, India

Venue: IOP Lecture Hall

Date: 2017-Mar-02 16:00:00

Abstract: Berry's discovery of the geometric phase in 1984 led to a deeper understanding of wide range of phenomena in different areas of physics starting from molecular physics to condensed matter systems. In this talk, I will first provide an introduction to the concept of geometric phase in spirit of Berry's definition and then relate it to its generalized version as anticipated in earlier works of Pancharatnam. I shall then apply Pancharatnam's ideas to obtain non-local and multi-particle geometric phase in the context of electronic version of the Hanbury-Brown and Twiss intensity interferometer. I will discuss a possible experimental realization of this effect by exploiting edge states of two-dimensional topological insulators (2d TI). It will be shown that the electrical transport in quantum spin Hall (an example of the 2d TI state) edge can host a two particle Aharonov - Bohm (AB) effect in spin space which essentially is an example of multi-particle and non-local geometric phase. This two particle “spin A-B effect” stems from an effective AB flux piercing a two particle loop identified on the Bloch sphere which can be attributed to an abstract monopole of strength 1/2 placed at the origin of the sphere.

Title: Different Facets of PT Symmetry

Speaker: Prof. A.Khare, Ex-Professor, IOP,

Venue: IOP Lecture Hall

Date: 2017-Mar-03 16:00:00

Abstract: In this talk I will discuss many interesting developments which have happened mainly in classical mechanics, Integrable models and classical field theory due to PT-symmetry. For example, I will discuss new reflectionless PT-symmetric potentials and hence complex PT-invariant solution of KdV equation. I also discuss new PT-invariant complex periodic solutions of KdV equation and conjecture that these potentials must have novel band structure. I then show that any model which admits kink solution, will always also admit PT-invariant complex kink solution and that it is also topologically stable. I further discuss stability of solitons of Nonlinear Schrodinger equation with PT-invariant complex potentials. I discuss a coupled oscillator model with balanced growth and loss and show that (unlike the single oscillator with friction) it is an Hamiltonian system. Finally I discuss PT-invariant Gross-Neuve model with N =1 (Soler model).