Thermal conductance and the Peltier coefficient of carbon nanotubes

Abstract

The -band structure of one-dimensional carbon nanotubes is very special. Their ballistic transport properties are studied theoretically and are found to exhibit rich magnetic-flux-dependent structures. The thermal conductance () has many step structures caused by the Zeeman splitting; a similar effect has been found in the electrical conductance G(). The Peltier coefficient ⌸() vanishes in the zero-voltage limit at any magnetic flux due to the symmetric -band structure about the chemical potential ϭ0. However, a finite Peltier effect could be observed by applying a finite voltage or by doping carbon nanotubes. Doping also causes peak structures with quantized maxima in ⌸(), as well as more step structures in (). Both the quantized peaks and the steps should be observable at TϽ1 K. These structures and also the validity of Wiedemann-Franz law ()Ϸ 2 k B 2 TG()/3e 2 are found to depend upon the temperature, the chemical potential, the -band property, and the Zeeman effect.

Electric-field induced modification of electronic properties of few-layer graphene nanoribbons

“…According to the Landauer-Buttiker theory, 45 in 1D GNRs, the net electric and thermal conductance could exhibit the quantized phenomena. 46 At very low temperature, the electrical and thermal conductance are proportional to the number of 1D subbands intersecting with the chemical potential. The energy gap could be easily modified by the electric field strength and direction so that the MST would occur in certain ranges of electric field strengths and directions.…”

Thermoelectric effects in STM tunneling through a monoatomic chain

“…In bulk systems, transport in the presence of electrical and thermal gradients is a well studied phenomenon. Recently, it became possible to study those effects, both experimentally and theoretically, in atomic-scale systems, like quantum point contacts [14,15], quantum dots [16]- [21], quantum dot superlattices [22], quantum wires with end atoms coupled to external leads [23], carbon nanotubes [24,25] or correlated multilayered nanostructures [26].…”

Reversible heat flow through the carbon tube junction

“…The sign reversal of α versus the sign of VG formerly observed experimentally is interpreted in this work in terms of so-called chiral tunneling phenomena (Klein paradox). Physics of the heat transfer determines functionality, precision and effectiveness of solid state nanocoolers [1,2,3,5] which are environment friendly and have a lot of applications in the experimental physics, nanoelectronics, chemistry, industry and medicine. Therefore exploiting of new thermoelectric materials with high figures of merit Z · T (T being the temperature) attracts a lot of attention.…”

“…-Physics of the heat transfer determines functionality, precision and effectiveness of solidstate nanocoolers which are environment friendly and have a lot of applications in the experimental physics, nanoelectronics, chemistry, industry, and medicine. Therefore exploiting of new thermoelectric materials with high figures of merit attracts a lot of attention [1][2][3][4]. Recently such interest arose toward the carbon tube and graphene junctions which electronic properties are highly unconventional [4][5][6][7][8][9][10].…”