Narrow Results

We investigate the band structure of narrow armchair-edge graphene nanoribbons (AGNRs) under tensile strain by means of an extension of the Extended Hückel method. The strain-induced band gap modulation presents asymmetric behavior. The asymmetric modulation of band gap is derived from the different changes of conduction and valence bands near Fermi level under tensile strain. Further analysis suggests that the asymmetric variation of band structure near Fermi level only appear in narrow armchair-edge graphene nanoribbons.

The transport properties in ultrasmall single-wall carbon nanotubes (SWCNTs) under tensile strain have been theoretically investigated. The regular negative differential resistance (NDR) induced by the strain undergoes a process from enhancement to weakening in the zigzag (3,0) SWCNT. The NDR achieves maximum with applying 4% tensile strain. Compared to the case of (3,0) SWCNT, that NDR cannot be manipulated by applying strain clearly in (4,0) and (5,0) ultrasmall SWCNTs with tensile strain lower than 10%. It proposes this strain-induced NDR effect to demonstrate the possibility of finding potential applications in SWCNT-based NDR nanodevices such as in memory devices, oscillators and fast switching devices.