Editing Nanowire (section)

== Characteristics ==
[[file:HgTe@SWCNT.png|thumb|A noise-filtered HRTEM image of a [[HgTe]] extreme nanowire embedded down the central pore of a SWCNT. The image is also accompanied by a simulation of the crystal structure<ref name=ExtremeNanowire>{{cite journal|doi=10.1021/nn5023632 |pmid=25163005 |title=Raman Spectroscopy of Optical Transitions and Vibrational Energies of ≈1 nm HgTe Extreme Nanowires within Single Walled Carbon Nanotubes |journal=ACS Nano |volume=8|issue=9 |pages=9044–52 |year=2014 |last1=Spencer |first1=Joseph |last2=Nesbitt |first2=John |last3=Trewhitt |first3=Harrison |last4=Kashtiban |first4=Reza |last5=Bell |first5=Gavin |last6=Ivanov |first6=Victor |last7=Faulques |first7=Eric |last8=Smith |first8=David|url=https://eprints.soton.ac.uk/401309/1/HgTe%2540SWNT_ACSNano_Final.pdf }}</ref>]]

Typical nanowires exhibit aspect ratios (length-to-width ratio) of 1000 or more. As such they are often referred to as one-dimensional (1-D) materials. Nanowires have many interesting properties that are not seen in bulk or 3-D (three-dimensional) materials. This is because [[electron]]s in nanowires are [[quantum]] confined laterally and thus occupy energy levels that are different from the traditional continuum of energy levels or bands found in bulk materials.

A consequence of this [[quantum confinement]] in nanowires is that they exhibit discrete values of the [[electrical conductance]]. Such discrete values arise from a quantum mechanical constraint on the number electronic transport channels at the nanometer scale, and they are often approximately equal to [[integer]] multiples of the [[quantum of conductance]]:
: <math>\frac{2e^2}{h} \simeq 77.41\; \mu S</math>

This conductance is twice the reciprocal of the resistance unit called the [[von Klitzing constant]], {{physconst|RK|symbol=yes|after=,}} defined as {{nowrap|1=''R''<sub>K</sub> = ''h''/''e''<sup>2</sup>}} and named for [[Klaus von Klitzing]], the discoverer of the [[quantum Hall effect|integer quantum Hall effect]].

Examples of nanowires include inorganic molecular nanowires (Mo<sub>6</sub>S<sub>9−''x''</sub>I<sub>''x''</sub>, Li<sub>2</sub>Mo<sub>6</sub>Se<sub>6</sub>), which can have a diameter of 0.9&nbsp;nm and be hundreds of micrometers long. Other important examples are based on semiconductors such as InP, Si, GaN, etc., dielectrics (e.g. SiO<sub>2</sub>,TiO<sub>2</sub>), or metals (e.g. Ni, Pt).

There are many applications where nanowires may become important in electronic, opto-electronic and nanoelectromechanical devices, as additives in advanced composites, for metallic interconnects in nanoscale quantum devices, as field-emitters and as leads for biomolecular nanosensors.