Positive Hanbury-Brown and Twiss correlations in superconducting hybrids: Role of interfaces and interactions
Shot noise cross-correlations in Normal metal-Superconductor-Normal metal structures are discussed at arbitrary interface transparencies. Negative crossed conductance in such set-ups does not preclude the possibility of positive noise cross correlations for almost transparent contacts, which is interpreted as the signature of processes having both features of two-electron cotunneling and of double non local electron-hole process. Further the sign of noise cross-correlations can be controlled via the interface transparencies. A phenomenological approach based on renormalization group is also attempted in order to describe qualitatively the effects of interaction in the normal electrodes. Interactions can induce sign changes in the noise crossed correlations, especially for moderate or large interface transparencies
04/09/2007 at 4:00 pm
Prof. S.Bhattacharya, Professor, TIFR , Mumbai
Spceial Colloquium
Lecture Hall
Document Date:
Protectionism and science: memories of underdevelopment
Protectionism and science: memories of underdevelopment
Development of scientific institutions in post-colonial India was driven by a patriotic conviction that science and technology will lead to prosperity for the underdeveloped and impoverished nation. At the same time, global political alignments and vivid memories of colonial exploitation led to a protectionist policy for the fledgling domestic industry. This protectionism spilled over to basic science enterprises as well and blended seamlessly with the prevailing feudal patronage system. An unintended casualty of this spillage was an uncompromising commitment to excellence, the key ingredient for developing a robust scientific culture. In such a weakened state Indian science became easy prey to political influence-peddling and what is now an institutionalized lack of accountability. Finding a national consensus to dismantle the apparatus of patronage and protectionism is an essential step towards initiating a much-needed rescue process today, when the country and its Government are able and willing to allocate vast financial resources towards the development of science and technology in the country.
29/08/2007 at 4:00 pm
Dr. Surajit Sengupta, SNBCBS, Kolkata
Seminar of General Interest
Lecture Hall
Document Date:
Non affine variables and microstructure selection in solids
Hard thermal loop effective actions are quite useful in studying properties of quark-gluon plasma. They arise from loop corrections at high temperature have very unique properties. In this talk we will try to discuss using the proper time method of Schwinger how such interesting properties arise in the structure of the hard thermal loop effective action
22/08/2007 at 4:00 pm
Mr.R. Amitshreeya, Department of Environmental Science, F.M. University, Balasore
Seminar of General Interest
Lecture Hall
Document Date:
Dust Pollution and its impact on stone crusher workers. A care study of Balgopalpur and Mitrapur