Aharonov-Bohm interference and beating in deformed single-walled carbon nanotube interferometers

The quantum conductance modulations induced by an axial magnetic field for deformed single-walled carbon nanotube (SWNT) interferometers under two types of deformation i.e., uniaxial tensile and torsional strains, have been studied in the tight-binding approximation. We have analytically derived the expression for the beating modulation period, which is caused by the Aharonov-Bohm interference between two nondegenerate subbands of spiraling electrons. It is found that the beating pseudoperiod is very sensitive to the type and strength of the applied strains, and also the chiral angle of the SWNT. For example, under tensile strain, all metallic SWNTs have the beating modulation except the armchair ones, while under torsional strain, only metallic zigzag SWNTs have no beating modulation. Therefore, the beating modulation could be a promising powerful tool to precisely measure experimentally the degee of nanoscale mechanical deformation of the deformed carbon nanotubes.