Related papers: Odd and even Kondo effects from emergent localisat…
Quantum devices such as spin qubits have been extensively investigated in electrostatically confined quantum dots using high-quality semiconductor heterostructures like GaAs and Si. Here, we present the first demonstration of…
We propose a theoretical model for the low-frequency noise observed in a quantum point contact (QPC) electrostatically defined in the 2D electron gas at a GaAs-AlGaAs interface. In such contacts electron scattering by soft impurity- or…
The quantum Hall effect arises from the interplay between localized and extended states that form when electrons, confined to two dimensions, are subject to a perpendicular magnetic field. The effect involves exact quantization of all the…
Quantum point contacts (QPC) are fundamental building blocks of nanoelectronic circuits. For their emission dynamics as well as for interaction effects such as the 0.7-anomaly the details of the electrostatic potential are important, but…
We report experimental results on a quantum point contact (QPC) device formed in a wide AlAs quantum well where the two-dimensional electrons occupy two in-plane valleys with elliptical Fermi contours. To probe the closely-spaced,…
Molecular electronics offers unique scientific and technological possibilities, resulting from both the nanometre scale of the devices and their reproducible chemical complexity. Two fundamental yet different effects, with no classical…
Spin-density-functional theory of quantum point contacts (QPCs) reveals the formation of a local moment with a net of one electron spin in the vicinity of the point contact - supporting the recent report of a Kondo effect in a QPC. The…
It is shown that recent experimental data on electronic transport through Pt nanocontacts in the presence of hydrogen admit an explanation in terms of topological and electron-electron correlation grounds. A model Hamiltonian, which…
We show experimentally how quantum interference can be produced using an integrated quantum system comprising an arch-shaped short quantum wire (or quantum point contact, QPC) of 1D electrons and a reflector forming an electronic cavity. On…
The interaction between a single confined spin and the spins of a Fermionic reservoir leads to one of the most spectacular phenomena of many body physics -- the Kondo effect. Here we report the observation of Kondo correlations in optical…
The quantum transport in a narrow channel (NC) is studied in the presence of a time-dependent delta-profile electric field. The electric field is taken to be transversely polarized, with frequency $\omega$, causing inter-subband and…
Entanglement entropy, which is a measure of quantum correlations between separate parts of a many-body system, has emerged recently as a fundamental quantity in broad areas of theoretical physics, from cosmology and field theory to…
We investigate theoretically quantum transport through the "charge" Kondo circuit consisting of the quantum dot (QD) coupled weakly to an electrode at temperature $T+\Delta T$ and connected strongly to another electrode at the reference…
Recent advances in atomic manipulation techniques have provided a novel bottom-up approach to investigating the unconventional properties and complex phases of strongly correlated electron materials. By engineering artificial condensed…
As the dimensions of a conductor approach the nano-scale, quantum effects will begin to dominate its behavior. This entails the exciting possibility of controlling the conductance of a device by direct manipulation of the electron wave…
We calculate the finite temperature and non-equilibrium electric current through systems described generically at low energy by a singlet and \emph{two} spin doublets for $N$ and $N \pm 1$ electrons respectively, coupled asymmetrically to…
We investigate the effects of the electron-electron interactions on the quantum transport through a charge Kondo circuit. The setup consists of a quantum dot sandwiched between two leads by two nearly transparent single mode quantum point…
We review our recent studies on the Kondo effect in the tunneling phenomena through quantum dot systems. Numerical methods to calculate reliable tunneling conductance are developed. In the first place, a case in which electrons of odd…
The linear transport properties of a model molecular transistor with electron-electron and electron-phonon interactions were investigated analytically and numerically. The model takes into account phonon modulation of the electronic energy…
We calculate the conductance through strongly correlated T-shaped molecular or quantum dot systems under the influence of phonons. The system is modelled by the extended Anderson-Holstein Hamiltonian. The finite-U mean-field slave boson…