4 ms·
Perhaps it's a topological insulator, so that the bulk conducts but you'd never know it because the surface doesn't. I'm a total noob, so if that is correct it
by dsfsdfd 11y ago
Perhaps it's a topological insulator, so that the bulk conducts but you'd never know it because the surface doesn't.
I'm a total noob, so if that is correct it's a miracle.
- morganvachon 11y agoThe article touches on that: "But this is no garden-variety insulator. Not only does its insulating behavior arise from strong correlations between its electrons, but in the past five years, mounting evidence has suggested that it is a “topological insulator” at low temperatures, a material that resists the flow of electricity through its three-dimensional bulk, while conducting electricity along its two-dimensional surfaces."
- kabouseng 11y agoAll conductors only conduct along their surface...unless I'm mistaken.
- morganvachon 11y agoNo, generally a thicker cable is a better conductor because its resistance is lower. If it were merely a matter of surface conductivity this wouldn't necessarily be true. However, internal conductivity and surface conductivity can be affected by magnetic fields: http://faculty.wwu.edu/vawter/physicsnet/Topics/Gauss/IdealCond.html http://faculty.wwu.edu/vawter/physicsnet/Topics/Gauss/IdealC...
- amelius 11y agoThere is also a tendency for currents to creep towards the surface of the conductor at high frequencies, see [1], although this is ultimately also caused by internally generated electromagnetic fields. [1] https://en.wikipedia.org/wiki/Skin_effect https://en.wikipedia.org/wiki/Skin_effect
- dalke 11y agoYou are somewhat mistaken. You are thinking of the skin effect. In DC power, current flow is proportional to the cross section. As the frequency increases, the effective resistance in the interior increases relative to the surface. At high enough frequencies, conductors effectively conduct only along the surface. See https://en.wikipedia.org/wiki/Skin_effect https://en.wikipedia.org/wiki/Skin_effect and https://en.wikipedia.org/wiki/Litz_wire https://en.wikipedia.org/wiki/Litz_wire .
- kabouseng 11y agoThank you, looks like I was mistaken :D
- techdragon 11y agoYou may be thinking of the skin effect associated with alternating current systems. https://en.m.wikipedia.org/wiki/Skin_effect https://en.m.wikipedia.org/wiki/Skin_effect
- chriswarbo 11y agoFor static charges, all of the charge on a conductor will be at its surface: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gausur.html http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gausur.h... That doesn't apply to moving charge though (ie. an electric current)
- gjm11 11y ago"...And yet, SMB6 does not neatly fit that category either."