CHARGE AND ENERGY-TRANSPORT BY TUNNELING THERMOELECTRIC EFFECT

Computational predictions, based upon conventional one-dimensional tun neling theory, are presented for charge and energy transport by electr on tunneling thermoelectric effect. It is shown that a temperature dif ference across a tunnel junction connected in an open electrical circu it produces a thermopower S and a heat conductance H(V). In a closed c ircuit, the temperature difference drives a tunnel current which is qu antified by a current conductance Q = \J(th)/DELTAT\LimDELTAT double-l ine arrow pointing right 0 (Where J(th) is the current density) and a heat conductance H(J). The thermopower S is shown to be relatively ins ensitive to image potentials and barrier thickness, whereas the transp ort coefficients Q, H(J), and H(V) are highly sensitive to junction pa rameters. The calculations for a ''generic'' Al-Al2O3-Al junction with a 25 angstrom barrier thickness indicate that S and Q could be measur able, whereas H(V) and H(J) are probably below the limits of detection . Although S might be measured by a scanning tunneling microscope, it is not clear at present how tip geometry would influence the measureme nt.