Many-body effects in electronic bandgaps of carbon nanotubes measured by scanning tunnelling spectroscopy

H. Lin (1) , J. Lagoute (2) , V. Repain (2) , C. Chacon (2) , Y. Girard (3) , J.-S Lauret , F. Ducastelle (1) , A. Loiseau (1) , S. Rousset (2)

1 LEM - ONERA - CNRS - Laboratoire d'étude des microstructures [Châtillon]
2 MPQ (UMR_7162) - Laboratoire Matériaux et Phénomènes Quantiques
3 INRETS/MA - Département Mécanismes d'Accidents

Single-walled carbon nanotubes provide an ideal system for studying the properties of one-dimensional (1D) materials, where strong electron-electron interactions are expected(1). Optical measurements have recently reported the existence of excitons in semiconducting nanotubes, revealing the importance of many-body effects(2-4). Surprisingly, pioneering electronic structure calculations(5-7) and scanning tunnelling spectroscopy (STS) experiments(8-10) report the same gap values as optical experiments. Here, an experimental STS study of the bandgap of single-walled semiconducting nanotubes, demonstrates a continuous transition from the gap reduced by the screening resulting from the metal substrate to the intrinsic gap dominated by many-body interactions. These results provide a deeper knowledge of many-body interactions in these 1D systems and a better understanding of their electronic properties, which is a prerequisite for any application of nanotubes in the ultimate device miniaturization for molecular electronics(11,12), or spintronics(13).

Domaines: Physique [physics]

H. Lin, J. Lagoute, V. Repain, C. Chacon, Y. Girard, et al.. Many-body effects in electronic bandgaps of carbon nanotubes measured by scanning tunnelling spectroscopy. Nature Materials, 2010, 9 (3), pp.235-238. ⟨hal-01987575⟩