Strain-induced Aharonov-Bohm effect at nanoscale and ground state of a carbon nanotube with zigzag edges

TL;DR

This paper demonstrates that uniaxial strain can induce Aharonov-Bohm-like oscillations in carbon nanotubes, significantly reducing the energy gap, with potential observable effects at the nanoscale.

Contribution

It introduces the concept that strain can mimic magnetic flux effects in nanotubes, extending the understanding of quantum oscillations beyond magnetic fields.

Findings

Strain induces Aharonov-Bohm-like oscillations in nanotubes.

Energy gap can be reduced by over 100 times due to strain.

Oscillations are observable at zero magnetic field.

Abstract

Magnetic flux piercing a carbon nanotube induce periodic gap oscillations which represent the Aharonov-Bohm effect at nanoscale. Here we point out, by analyzing numerically the anisotropic Hubbard model on a honeycomb lattice, that similar oscillations should be observable when uniaxial strain is applied to a nanotube. In both cases, a vector potential (magnetic- or strain-induced) may affect the measurable quantities at zero field. The analysis, carried out within the Gutzwiller Approximation, shows that for small semiconducting nanotube with zigzag edges and realistic value of the Hubbard repulsion ($U/t_0=1.6$, with $t_0\approx{}2.5\,$eV being the equilibrium hopping integral) energy gap can be reduced by a factor of more than $100$ due to the strain.