high-temperature superconductivity: the anisotropic state as a moment just before the kickoff

the phenomenon (high-temperature superconductivity) is marked by zero electrical resistance in some crystalline ceramic materials below a critical temperature. While very cold, the critical temperatures for high-temperature superconductors—between 50 and 150 kelvins above absolute zero—are relatively high in comparison with the temperatures required for conventional superconductivity.

Barium iron nickel arsenide (a high-temperature superconductor) is a composite crystal.

The atoms in the crystals form an ordered pattern that looks identical in both the right-left (x-axis) and forward-back (y-axis) directions, but not in the up-down (z-axis).

At room temperature, the material acts as one might expect, conducting electricity equally well along both its x-axis and y-axis. However, as the material is cooled to near the critical temperature for magnetism, it passes through a phase where electrical resistance is higher in one direction than the other. Physicists call directionally dependent behavior “anisotropic resistance”.

Explaining anisotropic state: the analogy of a crowd gathered at a stadium to watch a sporting event:
During the game, all eyes are on the field, and this is an ordered state that describes all the individuals in the crowd in relation to one another.
This state corresponds to the collective arrangement of electrons we see in magnetism and in superconductivity. The disordered arrangement we observe at room temperature, on the other hand, corresponds to the chaos we would see in the crowd one hour before the game begins, when people are turning from side to side and occasionally glancing at the field.
The anisotropic state corresponds to a moment just before the kickoff, when the individuals are still looking in random directions but are aware that the game is about to start.
The incoming neutron pulse (that triggers an anisotropic state) is the equivalent of someone blowing a whistle on the field. For a split second, the crowd reacts as one to the whistle, and every head turns to see if the game has begun. The individuals in the crowd quickly return to their random behavior, but the whistle has revealed an order that wasn’t present an hour before.

source: http://phys.org/news/2014-08-physical-link-strange-electronic-behavior.html

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