Thermoelectric properties of microstructures with four-probe versus two-probe setups

We study nonlocal thermoelectric transport properties of disordered mesoscopic systems in a four-probe setup. In particular, we vary the coupling of two of the probes to the sample. In the limit of weak coupling, 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 conductance and thermopower is also studied in the limit of strong coupling of the probes. {} 1996 The American Physical Society.