Hall effect

The Hall effect is the movement of charge carriers through a conductor towards a magnetic attraction. The phenomenon is named for Edwin Hall, who discovered the effect in 1879.

The Hall effect causes a measurable voltage differential across the conductor such that one side is positively charged and the other negatively. The effect is manipulated and measured in the functioning of many electronic devices including joystick-like controls, compasses in smartphones, magnetometers, sensors and current-measuring devices. On a large scale, the effect is harnessed in Hall effect thrusters (HET) that launch some crafts into space. In the natural world, the Hall effect plays a role in gravitational collapses that result in the formation of protostars.

electrons normally travel in a straight line. The Hall effect occurs with the production of a transverse force (Lorentz force) on the charge carriers moving through a conductor, such that they actively conduct a current in the presence of a perpendicular magnetic field. The magnet's north pole pulls the negative charge carriers (typically electrons) to the side of the conductor nearest the magnet. With all the flowing electrons of the carried current on one side of the conductor, that side is negatively charged and the other side is positively charged.

In a semiconductor, the effect is even greater as they have moving positive charge carriers, which are known as Halls. Halls are atoms that are positively charged, having lost one of their electrons. The positive charge carriers flow on the side of the semiconductor nearest the magnetic south pole, influencing the negative charge carriers on the side nearest the north pole. Both carriers are repelled by their opposing magnetic force.