Optimization in random field Ising models by quantum annealing

We investigate the properties of quantum annealing applied to the random field Ising model in one, two and three dimensions. The decay rate of the residual energy, defined as the energy excess from the ground state, is find to be $e_{res}\sim \log(N_{MC})^{-\zeta}$ with $\zeta$ in the range $2...6$, depending on the strength of the random field. Systems with ``large clusters'' are harder to optimize as measured by $\zeta$. Our numerical results suggest that in the ordered phase $\zeta=2$ whereas in the paramagnetic phase the annealing procedure can be tuned so that $\zeta\to6$.Comment: 7 pages (2 columns), 9 figures, published with minor changes, one reference updated after the publicatio

Elastic lines on splayed columnar defects studied numerically

We investigate by exact optimization method properties of two- and three-dimensional systems of elastic lines in presence of splayed columnar disorder. The ground state of many lines is separable both in 2d and 3d leading to a random walk -like roughening in 2d and ballistic behavior in 3d. Furthermore, we find that in the case of pure splayed columnar disorder in contrast to point disorder there is no entanglement transition in 3d. Entanglement can be triggered by perturbing the pure splay system with point defects.Comment: 9 pages, 11 figures. Accepted for publication in PR

Kihokin viljelyä lääkekasviksi Pohjois-Satakunnan turvemailla - kestävää biotaloutta

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Expression of catalase and retinoblastoma-related protein genes associates with cell death processes in Scots pine zygotic embryogenesis

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Round-leaved sundew (Drosera rotundifolia) as a source of naphthoquinones for pharmacological purposes

Posteri201

Does nitrate fertilization induce nox emission from scots pine (p. sylvestris) shoots?

Peer reviewe

Nitrogen release in decomposition of boreal mor and peat as affected by enchytraeid worms

Peer reviewe