ABSTRACT
We would like to stress the two important features of present-day thermoelectric investigations of quantum wires. First, diameters of Bi, Bi1-xSbx, InSb, BixTe1-x, and Si nanowires, whose thermoelectric properties have been experimentally studied [9-16], are relatively large (>10 nm). But according to theoretical estimates [4-7], only nanowires with diameters less than 10 nm can have values of ZT exceeding unity by several times. Second, all calculations of thermoelectric ›gure of merit of nanowires are based on the Fermi gas (Fermi liquid) model and essentially use quasiclassic Boltzmann equation formalism describing transport of charged quasiparticles. However, it is well known that, in onedimensional conductors, the Coulomb interaction cannot be considered as a small perturbation. In a one-dimensional wire, even weak electron-electron interaction leads to formation of the special state known as a Luttinger liquid [17-20]. še main feature of this state is the absence of individual excitations similar to the Fermi liquid quasiparticles. Only the collective phonon-like excitations exist in the electronic Luttinger liquid (LL). Moreover, the charge and spin excitations are independent of each other (spin-charge separation). A LL has a rather speci›c combination of transport properties. Its electrical
5.1 Introduction ...................................................................................... 5-1 5.2 Chrysotile Asbestos .......................................................................... 5-2 5.3 Electronic Transport in a Luttinger Liquid .................................. 5-3 5.4 InSb Nanowires ................................................................................. 5-5 5.5 Bi and Bi1-xSbx Nanowires ............................................................. 5-10 5.6 Concluding Remarks ...................................................................... 5-14 References .................................................................................................... 5-15
conductance [21,22] and the thermopower [23-26] grow simultaneously with increasing temperature. šerefore, calculations of the thermoelectric ›gure of merit of quantum wires based on the Fermi liquid model are inapplicable to ultrathin nanowires.
