Publications

@article{Samanta2004,
title = {Approach to equilibrium in adiabatically evolving potentials},
author = {H S Samanta, J K Bhattacharjee, and R Ramaswamy},
url = {https://link.aps.org/doi/10.1103/PhysRevE.69.056114},
doi = {10.1103/PhysRevE.69.056114},
year = {2004},
date = {2004-05-25},
journal = {Physical Review E},
volume = {69},
number = {5},
pages = {056114},
abstract = {For a potential function (in one dimension) which evolves from a specified initial form
V
i
(
x
)
to a different
V
f
(
x
)
asymptotically, we study the evolution, in an overdamped dynamics, of an initial probability density to its final equilibrium. There can be unexpected effects that can arise from the time dependence. We choose a time variation of the form
V
(
x
,
t
)
=
V
f
(
x
)
+
(
V
i
−
V
f
)
e
−
λ
t
. For a
V
f
(
x
)
, which is double welled and a
V
i
(
x
)
which is simple harmonic, we show that, in particular, if the evolution is adiabatic, this results in a decrease in the Kramers time characteristic of Vf(x)
. Thus the time dependence makes diffusion over a barrier more efficient. There can also be interesting resonance effects when
Vi(x)
and
Vf(x)
are two harmonic potentials displaced with respect to each other that arise from the coincidence of the intrinsic time scale characterizing the potential variation and the Kramers time. Both these features are illustrated through representative examples.},
keywords = {Adiabatic switching},
pubstate = {published},
tppubtype = {article}
}

@article{Hunjan2002,
title = {Global optimization by adiabatic switching},
author = {Jagtar S Hunjan and R Ramaswamy},
url = {https://ramramaswamy.org/papers/081.pdf},
doi = {10.3390/i3010030},
issn = {14220067},
year = {2002},
date = {2002-01-01},
journal = {International Journal of Molecular Sciences},
volume = {3},
number = {1},
pages = {30–37},
abstract = {We apply a recently introduced method for global optimization to determine the ground state energy and configuration for model metallic clusters. The global minimum for a given N-atom cluster is found by following the damped dynamics of the N particle system on an evolving potential energy surface. In this application, the time dependent interatomic potential interpolates adiabatically between the Lennard-Jones (LJ) and the Sutton-Chen (SC) forms. Starting with an ensemble of initial conditions corresponding to the ground state configuration of the Lennard-Jones cluster, the system asymptotically reaches the ground state of the Sutton-Chen cluster. We describe the method and present results for specific cluster size N=15, when the ground state symmetry of LJ$_N$ and SC$_N$ differ.},
keywords = {Adiabatic switching, Atomic Clusters, Global optimization, Ground states},
pubstate = {published},
tppubtype = {article}
}