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Vipin Kerala Varma

Publications and source records attributed to Vipin Kerala Varma.

20 records · Page 2Linked to original sources

arXiv2012

Lattice Green's functions for kagome, diced and hyperkagome lattices

Lattice Green's functions (LGF) and density of states (DOS) for non-interacting models on 3 related lattices are presented. The DOS and LGF at the origin for the kagome and diced lattices are rederived. Furthermore, from the form obtained for the DOS of the hyperkagome lattice, it seems highly suggestive that a closed form expression can be obtained if a particular complicated yet highly symmetrical integral can be solved. The results have been checked numerically. The continuum of energy states in the hyperkagome lattice and the appearance of a zero in the kagome lattice may be explicitly seen from the formulae obtained.

cond-mat.stat-mech↗

arXiv2011

Strong coupling expansion for bosons on the kagome lattice

We use series expansion techniques for analyzing properties of the phase transition between the Mott insulating and superfluid phase for bosons on the kagome lattice, and the multicritical point in the ground-state phase diagram for unit-filling is calculated. It is seen that of the clusters that contribute with non-zero weights to the ground state energy, many contain rings. The decay exponents of ground state correlations are also obtained within the Mott phase. For single-particle excited states, quasiparticle dispersion and effective masses for particles and holes are computed along certain symmetry cuts in the first Brillouin zone. Furthermore at eighth order, the coherence-length critical exponent is found to be comparably close to that of the 3D XY model.

cond-mat.str-el↗