Thermopower of a quantum dot in a coherent regime

Thermoelectric power due to coherent electron transmission through a quantum dot is theoretically studied. In addition to the known features related to resonant peaks, we show that a novel significant structure appears between the peaks. This structure arises from the so-called transmission zero, which is characteristic of coherent transmission through several quantum levels. Because of sensitivity to the phase-breaking effect in quantum dots, this novel structure indicates the degree of coherency in the electron transmission.