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S Khlebnikov

Publications and source records attributed to S Khlebnikov.

4 recordsLinked to original sources
PubMed2004

Quasiparticle scattering by quantum phase slips in one-dimensional superfluids.

Quantum phase slips (QPS) in narrow superfluid channels generate momentum by unwinding the supercurrent. In a uniform Bose gas, this momentum needs to be absorbed by quasiparticles (phonons). We show that this requirement results in an additional exponential suppression of the QPS rate (compared to the rate of QPS induced by a sharply localized perturbation). In BCS-paired fluids, momentum can be transferred to fermionic quasiparticles, and we find an interesting interplay between quasiparticle scattering on QPS and on disorder.

Journal Article↗
PubMed1999

Dynamics of lattice spins as a model of arrhythmia.

We consider evolution of initial disturbances in spatially extended systems with autonomous rhythmic activity, such as the heart. We consider the case when the activity is stable with respect to very smooth (changing little across the medium) disturbances and construct lattice models for description of not-so-smooth disturbances, in particular, topological defects; these models are modifications of the diffusive XY model. We find that when the activity on each lattice site is very rigid in maintaining its form, the topological defects--vortices or spirals--nucleate a transition to a disordered, turbulent state.

Arrhythmias, Cardiac↗