One-dimensional electron transport and thermopower in an individual InSb nanowire

Abstract

We have measured the electrical conductance and thermopower of a single InSb nanowire in the temperature range from 5 to 340 K. Below temperature (T) 220 K, the conductance (G) shows a power-law dependence on T and the current (I)-voltage (V) curve follows a power-law dependence on V at large bias voltages. These features are the characteristics of one-dimensional Luttinger liquid (LL) transport. The thermopower (S) also shows linear temperature dependence for T below 220 K, in agreement with the theoretical prediction based on the LL model. Above 220 K, the power law and linear behaviours respectively in the G-T and S-T curves persist but with different slopes from those at low temperatures. The slope changes can be explained by a transition from a single-mode LL state to a multi-mode LL state.

Thermoelectric Properties of InSb Nanowires Over a Wide Temperature Range

“…7 Therefore, the higher thermopower of our nanowires compared with that measured in Ref. 4 can arise because of larger electron-electron interaction.…”

“…Among these structures, electronic properties of quasi-one-dimensional wires are of special interest because the enhanced electron-electron interaction results in the formation of the unusual state of the electronic subsystem called a Luttinger liquid. 1 The characteristic features of the transport properties of a Luttinger liquid were revealed in experimental results on electrical conductance and current-voltage characteristics of InSb, [2][3][4] Bi 1Àx Sb x , 5 NbSe 3 , 6 and MoSe nanowires 7 ; polymer nanofibers 8 ; carbon nanotubes [9][10][11] ; and fractional quantum Hall edge states. 12 Luttinger liquid behavior of the thermoelectric power was revealed in InSb nanowires 3,4 and carbon nanotubes.…”

“…1 The characteristic features of the transport properties of a Luttinger liquid were revealed in experimental results on electrical conductance and current-voltage characteristics of InSb, [2][3][4] Bi 1Àx Sb x , 5 NbSe 3 , 6 and MoSe nanowires 7 ; polymer nanofibers 8 ; carbon nanotubes [9][10][11] ; and fractional quantum Hall edge states. 12 Luttinger liquid behavior of the thermoelectric power was revealed in InSb nanowires 3,4 and carbon nanotubes. 11 The important feature of the Luttinger liquid is a strong increase of power factor S 2 r (where S is the thermopower and r is the electrical conductivity) with increasing temperature, which is favorable for thermoelectric applications.…”

Nanowires in Thermoelectric Devices

“…A significantly different thermopower with an opposite sign was also reported for bismuth nanowires with a diameter of 150-480 nm in comparison with bulk bismuth [67]. Theoretical predictions by Mingo [33] showed InSb as an excellent thermoelectric material with a large figure of merit for a nanowire with a diameter around 20 nm, but when Zhou et al [58] found that the thermopower of a 40 nm wire did not increase even relative to bulk InSb. This discrepancy was attributed to phonon effects or energy spectrum dispersion near the Fermi level.…”

“…Subsequently, gold (or Pt) electrical contacts are fabricated using photolithography and electron beam evaporation. One of the electrodes acts as a heater, and Joule heating through a heater line is used to establish a temperature difference which generates a thermoelectric voltage in the nanowire [56][57][58]. The Seebeck coefficient of the nanowire is calculated using ΔT and measuring the Seebeck voltage.…”