Princeton University

Title: Devil's staircase of incompressible electron states in a nanotube

Abstract: Coupling of the nanotube electrons to an external periodic potential is suggested as a means to demonstrate and study effects of strong electron interactions, including Wigner crystallization, commensurate-incommensurate transitions, Tomonaga-Luttinger correlations, and spin excitations of high symmetry. Electron interactions result in a devil's staircase of incompressible states that correspond to the electron density commensurate with the potential period. Excitation gaps are estimated as an energy of the phase soliton that describes a slow deformation of the regular configuration of electrons locked by the external potential. Incompressible states can be detected in the adiabatic transport setup proposed in [V.I. Talyanskii, D.S. Novikov, B.D. Simons, L.S. Levitov, Phys. Rev. Lett. 87, 276802 (2001)]. Such a setup could realize the quantum-mechanical version of an Archimedean screw that pumps on average a fraction of an electron charge per cycle, operating by virtue of electron-electron interactions.

References: D.S. Novikov, cond-mat/0412456 (short), cond-mat/0407498 (long)