Electron correlation effects in transport and tunneling spectroscopy of the Si(111)-$7\times 7$ surface

Abstract

Electronic properties of the Si(111)-$7\times 7$ surface are studied using four- and two-probe conductivity measurements and tunneling spectroscopy. We demonstrate that the temperature dependence of the surface conductivity corresponds to the Efros-Shklovskii law at least in $10-100$~K temperature range. The energy gap at the Fermi level observed in tunneling spectroscopy measurements at $T\ge 5$~K vanishes by thermal fluctuations at $T\approx 30$~K, without any sign of the metal-insulator transition. We show that the low-temperature energy gap observed by the tunneling spectroscopy technique is actually the consequence of the Coulomb blockade effect.

5 pages, 5 figures, alternations in the text and figures

References in corpus (2)

• Dynamical Coulomb Blockade Observed in Nano-Sized Electrical Contacts
• Energy gap revealed by low-temperature scanning-tunnelling spectroscopy of Si(111)-7x7 surface in illuminated slightly-doped crystals

Cited by in corpus (3)

• Low-Temperature Insulating Phase of the Si(111)--7$\times$7 Surface
• Electronic correlation effects and Coulomb gap in the Si(111)-$(\sqrt{3}\times \sqrt{3})$-Sn surface
• Theoretical proposal to obtain strong Majorana evidence from scanning tunneling spectroscopy of a vortex with a dissipative environment