4 papers
Quantum Treatment of the Anderson-Hasegawa Model -- Effects of Superexchange and Polarons
Manidipa Mitra, P. A. Sreeram, Sushanta Dattagupta
We revisit the Anderson-Hasegawa double-exchange model and critically examine its exact solution when the core spins are treated quantum mechanically.We show that the quantum effec…
A look at the crossover region between BCS superconductivity and Bose Einstein Condensation
P. A. Sreeram, Suresh G. Mishra
Pair fluctuation theory has been used to study the crossover from the weak coupling BCS theory to the strong coupling Bose Einstein Condensation. The effect of fluctuations has bee…
Crossing of Specific Heat Curves in Liquid Helium 3 and Heavy Fermion Systems
Suresh G. Mishra, P. A. Sreeram
Specific heat curves for various pressures, in many correlated electron systems, have been seen to cross at a point. We analyze this behavior using the spin fluctuation theory. It…
Essential Differences between and Axis Tunneling and Zero Bias Conductance in the Cuprates
P. A. Sreeram, Manas Sardar
The peculiarities in tunneling characteristics have been studied in the light of the controversy between s-wave and d-wave character of High superconductivity. We show that a…