Analytic expression for pull-or-jerk experiment

This work focuses on a theoretical analysis of a well-known inertia demonstration, which uses a weight suspended by a string with an extra string that hangs below the weight. The point in question is which string, the upper or lower, will break when pulling down on the bottom edge of the lower string at a constant pulling speed. An analytic solution for the equation of motion allows us to identify the critical value of the pulling speed, beyond which the string breaking varies from one to the other. The analysis also provides us a phase diagram that illustrates the interplay between the pulling speed and the string's elasticity in the pull-or-jerk experiment.Comment: 12 pages, 5 figures; To appear in Eur. J. Phys. (2014

Dielectric anomaly in coupled rotor systems

The correlated dynamics of coupled quantum rotors carrying electric dipole moment is theoretically investigated. The energy spectra of coupled rotors as a function of dipolar interaction energy is analytically solved. The calculated dielectric susceptibilities of the system show the peculiar temperature dependence different from that of isolated rotors.Comment: 5 pages, 4 figures (Figure 2 is available on request from [email protected]

Survival of short-range order in the Ising model on negatively curved surfaces

We examine the ordering behavior of the ferromagnetic Ising lattice model defined on a surface with a constant negative curvature. Small-sized ferromagnetic domains are observed to exist at temperatures far greater than the critical temperature, at which the inner core region of the lattice undergoes a mean-field phase transition. The survival of short-range order at such high temperatures can be attributed to strong boundary-spin contributions to the ordering mechanism, as a result of which boundary effects remain active even within the thermodynamic limit. Our results are consistent with the previous finding of disorder-free Griffiths phase that is stable at temperatures lower than the mean-field critical temperature.Comment: 6 pages, 6 figure

Continuous Transition of Defect Configuration in a Deformed Liquid Crystal Film

We investigate energetically favorable configurations of point disclinations in nematic films having a bump geometry. Gradual expansion in the bump width {\Delta} gives rise to a sudden shift in the stable position of the disclinations from the top to the skirt of the bump. The positional shift observed across a threshold {\Delta}th obeys a power law function of |{\Delta}-{\Delta}th|, indicating a new class of continuous phase transition that governs the defect configuration in curved nematic films.Comment: 8pages, 3figure