New resistivity for high-mobility quantum Hall conductors

We present measurements showing dramatic nonlocal behavior in the four-terminal resistances of a high-mobility quantum Hall conductor. These measurements illustrate that the standard definition of the resistivity tensor is inappropriate, but they are in excellent agreement with a new model of the conductor that treats the edge and bulk conducting pathways independently. This model uses a single intensive parameter, analogous to a local resistivity for the bulk channel only, to characterize the system.