1,899 research outputs found
Torpid Mixing of Markov Chains for the Six-vertex Model on Z^2
In this paper, we study the mixing time of two widely used Markov chain algorithms for the six-vertex model, Glauber dynamics and the directed-loop algorithm, on the square lattice Z^2. We prove, for the first time that, on finite regions of the square lattice these Markov chains are torpidly mixing under parameter settings in the ferroelectric phase and the anti-ferroelectric phase
Strain-induced pseudomagnetic field and quantum oscillations in kagome crystals
A kagome lattice is composed of corner-sharing triangles arranged on a
honeycomb lattice such that each honeycomb bond hosts a kagome site while each
kagome triangle encloses a honeycomb site. Such close relation implies that the
two lattices share common features. We predict here that a kagome crystal,
similar to the honeycomb lattice graphene, reacts to elastic strain in a unique
way that the bulk electronic states in the vicinity of Dirac points are
reorganized by the strain-induced pseudomagnetic field into flat Landau levels,
while the degenerate edge states in the undeformed crystal become separated in
the energy dimension. When the strain is tuned continuously, the resulting
scanning pseudomagnetic field gives rise to quantum oscillations in both
density of states (DOS) and electric conductivity.Comment: 8 pages, 5 figure
Electric Control of Spin Currents and Spin-Wave Logic
Spin waves in insulating magnets are ideal carriers for spin currents with
low energy dissipation. An electric field can modify the dispersion of spin
waves, by directly affecting, via spin-orbit coupling, the electrons that
mediate the interaction between magnetic ions. Our microscopic calculations
based on the super-exchange model indicate that this effect of the electric
field is sufficiently large to be used to effectively control spin currents. We
apply these findings to the design of a spin-wave interferometric device, which
acts as a logic inverter and can be used as a building block for
room-temperature, low-dissipation logic circuits.Comment: 4 pages, 3 figures, added the LL equation and the discussion on
spin-wave-induced electric field, accepted by PR
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