Related papers: Persistent Orbital Degeneracy in Carbon Nanotubes
We systematically study the coupling of longitudinal modes (shells) in a carbon nanotube quantum dot. Inelastic cotunneling spectroscopy is used to probe the excitation spectrum in parallel, perpendicular and rotating magnetic fields. The…
Single wall carbon nanotubes cooled to cryogenic temperatures are outstanding electronic as well as nano-electromechanical model systems. To probe a largely unperturbed system, we measure a suspended carbon-nanotube device where the…
First-principles simulations were performed to investigate reaction of carbon nanotubes with adsorbed metal atoms. Mechanical modification of their structures enhances chemical reactivity of carbon nanotubes. Adsorption of a tungsten,…
We consider clean cylindrical nanostructures with an applied longitudinal static magnetic field. Without Coulomb interaction, the field induces, for particular values, points of degeneracy where a change of ground state takes place due to…
We report the observation of Coulomb drag between a two-dimensional (2D) electron gas in graphene and a one-dimensional (1D) wire composed of a carbon nanotube. We find that drag occurs when the bulk of graphene is conducting, but is…
We investigate the electron transport in multiply connected metallic carbon nanotubes within the Landauer-B\"{u}ttiker formalism. Quasibound states coupled to the incident $\pi^{*}$ states give rise to energy levels of different widths…
We report influence of encapsulated C60 molecules on electron transport in carbon-nanotube peapod quantum dots. We find atomic-like behaviors with doubly degenerate electronic levels, which exist only around ground states, by single…
A suspended carbon nanotube can act as a nanoscale resonator with remarkable electromechanical properties and the ability to detect adsorption on its surface at the level of single atoms. Understanding adsorption on nanotubes and other…
We investigate linear and nonlinear transport across single-walled carbon nanotube quantum dots weakly coupled to spin-polarized leads. We consider tubes of finite length and small diameter, where not only forward scattering contributions…
We report Pauli spin blockade in an impurity defined carbon nanotube double quantum dot. We observe a pronounced current suppression for negative source-drain bias voltages which is investigated for both symmetric and asymmetric coupling of…
We show theoretically that an undoped carbon nanotube might be an excitonic insulator---the long-sought phase of matter proposed by Keldysh, Kohn and others fifty years ago. We predict that the condensation of triplet excitons, driven by…
A graphene nanoribbon (GNR) with orientation along its principle axis was obtained through a mechanical tearing process, and a quantum dot device was fabricated from the GNR. We have studied the transport property of the GNR quantum dot…
Angular perturbations modify the band structure of armchair (and other metallic) carbon nanotubes by breaking the tube symmetry and may induce a metal-semiconductor transition when certain selection rules are satisfied. The symmetry…
We report electrical transport measurements through a semiconducting single-walled carbon nanotube (SWNT) with three additional top-gates. At low temperatures the system acts as a double quantum dot with large inter-dot tunnel coupling…
The Hubbard model for electrons with orbital degeneracy is shown to have an underlying SU_d(4) symmetry of spin-orbital double. A hidden charge SU_c(4) symmetry is exposed and an extended Lieb-Mattis transformation which maps these two…
Low-temperature transport spectroscopy measurements on a suspended few-hole carbon nanotube quantum dot are presented, showing a gate-dependent harmonic excitation spectrum which, strikingly, occurs in the Coulomb blockade regime. The…
Stable cross-sections of multi-walled carbon nanotubes subjected to electron-beam irradiation are investigated in the realm of the continuum mechanics approximation. The self-healing nature of sp$^2$ graphitic sheets implies that selective…
We study the Kondo effect in a CNT(left lead)-CNT(QD)-CNT(right lead) structure. Here CNT is a single-wall metallic carbon nanotube, for which 1) the valence and conduction bands of electrons with zero orbital angular momentum ($m=0$)…
For a capacitor made of a semiconducting carbon nanotube (CNT) suspended above a metallic gate, Coulomb correlations between individual electrons can lead to a capacitance that is much larger than the geometric capacitance. We argue that…
We have theoretically investigated electromechanical properties of freely suspended carbon nanotubes when a current is injected into the tubes using a scanning tunneling microscope. We show that a shuttle-like electromechanical instability…