• Publications
  • Influence
Memory in nanomagnetic systems: superparamagnetism versus spin-glass behavior
The slow dynamics and concomitant memory (aging) effects seen in nanomagnetic systems are analyzed on the basis of two separate paradigms: superparamagnets and spin glasses. It is argued that in a
Raman study of orientational dynamics of sulphate ions in potash alum Dattagupta
The Ag internal mode of the sulphate ion in potash alum is studied by Raman scattering as a function of temperature. This mode shows a splitting on account of the fact that a small fraction of S-O
Study of time-dependent hyperfine interactions by PAC, Mössbauer effect, μSR and NMR: A review of stochastic models
Time-dependent hyperfine interactions constitute a useful nuclear tool for probing interactions in condensed matter. The hyperfine coupling between, say, a nucleus and its surrounding electrons in an
Signal to noise enhancement of lock‐in amplifiers
A lock‐in amplifier can be considered to be a special case of the more general box‐car averager. Expressions for the output noise voltage of lock‐in amplifiers are deduced from the corresponding
Stochastic theory of line shape. II. Nonsecular effects in the EPR spectrum of C O 2 − in calcite
The random-phase-approximation result derived in the preceding paper is used to study the EPR line shape of CO 2 - defects in CaCO 3 . Relaxation is caused by a thermally activated mechanism due to
Landau diamagnetism revisited
The problem of diamagnetism, solved by Landau, continues to pose fascinating issues which have relevance even today. These issues relate to inherent quantum nature of the problem, the role of
Stochastic theory of line shape. I. Nonsecular effects in the strong-collision model
Starting from a general stochastic-theory result in which the Hamiltonian is taken to jump at random between a number of forms, due, for example, to spin-spin or spin-lattice relaxation, we treat a