Interplay of Coulomb Blockade and Luttinger-Liquid Physics in Disordered 1D InAs Nanowires with Strong Spin-Orbit Coupling

Ballistic 1D nanowires (NWs) with strong spin-orbit coupling are theoretically predicted to exhibit nonmonotonic conductance steps of size G0=e2/h as the electron density is varied by the gate voltage VG. Although many attempts have been made to measure these conductance steps, they have not been observed yet in either InAs or InSb NWs. This indicates that disorder plays an essential role, preventing the motion of the electrons between the contacts from being ballistic. It is well known that in 1D systems, electron-electron interactions, described by the Luttinger-liquid (LL) model, amplify the role of disorder significantly, causing the conductance to vanish at zero temperature even for very weak disorder. Experimentally, however, the effects of the interactions in NWs with strong spin-orbital scattering have not yet been reported. This chapter reports on experimental studies of the Coulomb blockade in disordered InAs NW at low temperatures. It demonstrates that sequential tunneling is strongly affected by electron-electron interactions.