THERMOELECTRIC PROPERTIES OF MICROSTRUCTURES WITH 4-PROBE VERSUS 2-PROBE SETUPS

We study nonlocal thermoelectric transport properties of disordered me soscopic systems in a four-probe setup. In particular, we vary the cou pling of two of the probes to the sample. In the limit of weak couplin g, we recover the two-probe thermoelectric transport coefficients. We find that the Onsager relations are satisfied in the disordered region . The effect of phase-incoherent transport on the two-probe conductanc e and thermopower is also studied in the limit of strong coupling of t he probes.