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Anatoly Kuklov

Publications and source records attributed to Anatoly Kuklov.

40 records · Page 3Linked to original sources
arXiv2004

Superfluid Interfaces in Quantum Solids

One scenario for the non-classical moment of inertia of solid He-4 discovered by Kim and Chan [Nature 427, 225 (2004)] is the superfluidity of micro-crystallite interfaces. On the basis of the most simple model of a quantum crystal--the checkerboard lattice solid--we show that the superfluidity of interfaces between solid domains can exist in a wide range of parameters. At strong enough inter-particle interaction, a superfluid interface becomes an insulator via a quantum phase transition. Under the conditions of particle-hole symmetry, the transition is of the standard U(1) universality class in 3D, while in 2D the onset of superfluidity is accompanied by the interface roughening, driven by fractionally charged topological excitations.

cond-mat.other↗
arXiv2004

Weak first-order superfluid--solid quantum phase transitions

We study superfluid--solid zero-temperature transitions in two-dimensional lattice boson/spin models by Worm-Algorithm Monte Carlo simulations. We observe that such transitions are typically first-order with the exception of special high-symmetry points which require fine tuning in the Hamiltonian parameter space. We present evidence that the superfluid--checkerboard solid and superfluid--valence-bond solid transitions at half-integer filling factor are extremely weak first-order transitions and in small systems they may be confused with continuous or high-symmetry points.

cond-mat.stat-mech↗
arXiv2003

Commensurate Two-Component Bosons in Optical Lattice: Groundstate Phase Diagram

Two sorts of bosons in an optical lattice at commensurate filling factors can form five stable superfluid and insulating groundstates with rich and non-trivial phase diagram. The structure of the groundstate diagram is established by mapping $d$-dimensional quantum system onto a $(d+1)$-dimensional classical loop-current model and Monte Carlo simulations of the latter. Surprisingly, the quantum phase diagram features, besides second-order lines, a first-order transition and two multi-critical points. We explain why first-order transitions are generic for models with paring interactions using microscopic and mean-field arguments.

cond-mat.soft↗