Interaction enhanced thermopower in a Luttinger liquid

The thermopower S-L(T) of a finite Luttinger liquid (LL) wire containing an impurity and connected to leads of noninteracting electrons is calculated. It is shown that at low temperatures k(B)T much less than Delta (L)similar or equal to(h) over barv(F)/gL (L is the length of the wire, v(F) is the Fermi velocity of the electrons, and g is the correlation parameter of the LL), S-L(T) is described by a Mott-type formula. However, at higher temperatures, that is, when Delta (L)less than or equal to k(B)T much less than epsilon (F), the expression for S-L(T) contains an interaction-dependent factor. For strong interelectron interaction, the enhancement of the thermopower is large and it is much more pronounced for spinless electrons.