120 citations · 576 across the 38 of their papers we have counts for
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Spin Tunneling in Magnetic Molecules: Quasisingular Perturbations and Discontinuous SU(2) Instantons
Ersin Kececioglu, Anupam Garg
Spin coherent state path integrals with discontinuous semiclassical paths are investigated with special reference to a realistic model for the magnetic degrees of freedom in the Fe…
Spin Coherent-State Path Integrals and the Instanton Calculus
Anupam Garg, Evgueny Kochetov, Kee-Su Park +1
We use an instanton approximation to the continuous-time spin coherent-state path integral to obtain the tunnel splitting of classically degenerate ground states. We show that prov…
Diabolical Points in Molecular Magnets with a Four-Fold Easy Axis
Chang-Soo Park, Anupam Garg
We study the points of degeneracy (diabolical points) in magnetic molecules such as Mn_{12}-acetate that have an easy axis of four-fold symmetry. This is done for general magnetic…
The Semiclassical Propagator for Spin Coherent States
Michael Stone, Kee-Su Park, Anupam Garg
We use a continuous-time path integral to obtain the semiclassical propagator for minimal-spread spin coherent states. We pay particular attention to the ``extra phase'' discovered…
Quenched Spin Tunneling and Diabolical Points in Magnetic Molecules: II. Asymmetric Configurations
Anupam Garg
The perfect quenching of spin tunneling first predicted for a model with biaxial symmetry, and recently observed in the magnetic molecule Fe_8, is further studied using the discret…
Tunnel splittings for one dimensional potential wells revisited
Anupam Garg
The WKB and instanton answers for the tunnel splitting of the ground state in a symmetric double well potential are both reduced to an expression involving only the functionals of…
Quenched Spin Tunneling and Diabolical Points in Magnetic Molecules: I. Symmetric Configurations
Anupam Garg
The perfect quenching of spin tunneling that has previously been discussed in terms of interfering instantons, and has recently been observed in the magnetic molecule \Fe8, is trea…
Diabolical points in the magnetic spectrum of Fe_8 molecules
Anupam Garg
The magnetic molecule Fe_8 has been predicted and observed to have a rich pattern of degeneracies in its spectrum as an external magnetic field is varied. These degeneracies have n…
Coherent Magnetic Moment Reversal in Small Particles with Nuclear Spins
Anupam Garg
A discrete WKB method is developed for calculating tunnel splittings in spin problems. The method is then applied to the issue of how nuclear spins affect the macroscopic quantum c…
Application of the discrete Wentzel-Kramers-Brillouin method to spin tunneling
Anupam Garg
A discrete version of the WKB method is developed and applied to calculate the tunnel splittings between classically degenerate states of spin Hamiltonians. The results for particu…
Oscillatory Tunnel Splittings in Spin Systems: A Discrete Wentzel-Kramers-Brillouin Approach
Anupam Garg
Certain spin Hamiltonians that give rise to tunnel splittings that are viewed in terms of interfering instanton trajectories, are restudied using a discrete WKB method, that is mor…
Large transverse field tunnel splittings in the Fe_8 spin Hamiltonian
Anupam Garg
The spin Hamiltonian that describes the molecular magnet Fe has biaxial symmetry with mutually perpendicular easy, medium, and hard magnetic axes. Previous calculations of the…
Lattice Distortion Mediated Paramagnetic Relaxation in High-Spin High-Symmetry Molecular Magnets
Anupam Garg
Field-dependent maxima in the relaxation rate of the magnetic molecules Mn_12-Ac and Fe_8-tacn have commonly been ascribed to some resonant tunneling phenomenon. We argue instead t…