We study Coulomb blockade oscillations of thermoelectric coefficients of a single-electron transistor based on a quantum dot strongly coupled to one of the leads by a quantum point contact. At temperatures below the charging energy EC the transport of electrons is dominated by strong inelastic cotunneling. In this regime we find analytic expressions for the thermopower as a function of temperature T and the reflection amplitude r in the contact. In the case when the electron spins are polarized by a strong external magnetic field, the thermopower shows sinusoidal oscillations as a function of the gate voltage with the amplitude of the order of e-1 r(T/EC). We obtain qualitatively different results in the absence of the magnetic field. At temperatures between EC and ECr2 the thermopower oscillations are sinusoidal with the amplitude of order e-1r21n(EC/T). On the other hand, at TECr2 we find nonsinusoidal oscillations of the thermopower with the amplitude we ∼e -1r√T/EC1n(EC/T.
|Number of pages||4077105|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 15 Jul 2002|