Localized edge vibrations and edge reconstruction by Joule heating in graphene nanostructures (2009)
Engelund, Mads, Furst, Joachim, Brandbyge, Mads, Jauho, Antti-Pekka
Control of the edge topology of graphene nanostructures is critical to graphene-based electronics. A means of producing atomically smooth zigzag edges using electronic current has recently been...
Atomic carbon chains as spin-filters: an \textit{Ab initio} transport study (2009)
Fuerst, Joachim A., Brandbyge, Mads, Jauho, Antti-Pekka
An atomic carbon chain joining two graphene flakes was very recently realized in a ground-breaking experiment by Jin {\it et al.}, Phys. Rev. Lett. {\bf 102}, 205501 (2009). We present {\it ab...
Electronic properties of graphene antidot lattices (2009)
Fuerst, Joachim A., Pedersen, Jesper G., Flindt, Christian, Mortensen, Niels Asger, Brandbyge, Mads, Pedersen, Thomas G., ...
Graphene antidot lattices constitute a novel class of nano-engineered graphene devices with controllable electronic and optical properties. An antidot lattice consists of a periodic array of holes...
Atomistic theory for the damping of vibrational modes in mono-atomic gold chains (2009)
Engelund, Mads, Brandbyge, Mads, Jauho, Antti-Pekka
We develop a computational method for evaluating the damping of vibrational modes in mono-atomic metallic chains suspended between bulk crystals under external strain. The damping is due to the...
DFT study of graphene antidot lattices: The roles of geometry relaxation and spin (2009)
Fuerst, Joachim A., Pedersen, Thomas G., Brandbyge, Mads, Jauho, Antti-Pekka
Graphene sheets with regular perforations, dubbed as antidot lattices, have theoretically been predicted to have a number of interesting properties. Their recent experimental realization with lattice...
Heat conductance is strongly anisotropic for pristine silicon nanowires (2009)
Markussen, Troels, Jauho, Antti-Pekka, Brandbyge, Mads
We compute atomistically the heat conductance for ultra-thin pristine silicon nanowires (SiNWs) with diameters ranging from 1 to 5 nm. The room temperature thermal conductance is found to be highly...
Thermal rectification in nonlinear quantum circuits (2008)
Ruokola, Tomi, Ojanen, Teemu, Jauho, Antti-Pekka
We present a theoretical study of radiative heat transport in nonlinear solid-state quantum circuits. We give a detailed account of heat rectification effects, i.e. the asymmetry of heat current with...
Markussen, Troels, Jauho, Antti-Pekka, Brandbyge, Mads
We compute both electron- and phonon transmissions in thin disordered silicon nanowires. Our atomistic approach is based on tight-binding and empirical potential descriptions of the electronic and...
Nanostructure design for surface-enhanced Raman spectroscopy - prospects and limits (2008)
Xiao, Sanshui, Mortensen, Niels Asger, Jauho, Antti-Pekka
Surface-enhanced Raman spectroscopy (SERS) allows single-molecule detection due to the strong field localization occurring at sharp bends or kinks of the metal-vacuum interface. An important question...
Optical properties of graphene antidot lattices (2008)
Pedersen, Thomas G., Flindt, Christian, Pedersen, Jesper, Jauho, Antti-Pekka, Mortensen, Niels Asger, Pedersen, Kjeld
Undoped graphene is semi-metallic and thus not suitable for many electronic and optoelectronic applications requiring gapped semiconductor materials. However, a periodic array of holes (antidot...
Graphene Antidot Lattices - Designed Defects and Spin Qubits (2008)
Pedersen, Thomas G., Flindt, Christian, Pedersen, Jesper, Mortensen, Niels Asger, Jauho, Antti-Pekka, Pedersen, Kjeld
Antidot lattices, defined on a two-dimensional electron gas at a semiconductor heterostructure, are a well-studied class of man-made structures with intriguing physical properties. We point out that...
Fürst, Joachim A., Brandbyge, Mads, Jauho, Antti-Pekka, Stokbro, Kurt
We present an ab initio study of spin dependent transport in armchair carbon nanotubes with transition metal adsorbates, iron or vanadium. We neglect the effect of tube curvature and model the...
Transport in Silicon Nanowires: Role of Radial Dopant Profile (2008)
Markussen, Troels, Rurali, Riccardo, Jauho, Antti-Pekka, Brandbyge, Mads
We consider the electronic transport properties of phosphorus (P) doped silicon nanowires (SiNWs). By combining ab initio density functional theory (DFT) calculations with a recursive Green's...
Designed defects in 2D antidot lattices for quantum information processing (2008)
Pedersen, Jesper, Flindt, Christian, Mortensen, Niels Asger, Jauho, Antti-Pekka
We propose a new physical implementation of spin qubits for quantum information processing, namely defect states in antidot lattices defined in the two-dimensional electron gas at a semiconductor...
Spin qubits in antidot lattices (2008)
Pedersen, Jesper, Flindt, Christian, Mortensen, Niels Asger, Jauho, Antti-Pekka
We suggest and study designed defects in an otherwise periodic potential modulation of a two-dimensional electron gas as an alternative approach to electron spin based quantum information processing...
Counting Statistics of Non-Markovian Quantum Stochastic Processes (2008)
Flindt, Christian, Novotny, Tomas, Braggio, Alessandro, Sassetti, Maura, Jauho, Antti-Pekka
We derive a general expression for the cumulant generating function (CGF) of non-Markovian quantum stochastic transport processes. The long-time limit of the CGF is determined by a single dominating...
Mesoscopic photon heat transistor (2007)
Ojanen, Teemu, Jauho, Antti-Pekka
We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit - leading to the device concept Mesoscopic Photon...
Markussen, Troels, Rurali, Riccardo, Jauho, Antti-Pekka, Brandbyge, Mads
We combine the ideas of scaling theory and universal conductance fluctuations with density-functional theory to analyze the conductance properties of doped silicon nanowires. Specifically, we study...
Failure of standard approximations of the exchange coupling in nanostructures (2007)
Pedersen, Jesper, Flindt, Christian, Mortensen, Niels Asger, Jauho, Antti-Pekka
We calculate the exchange coupling for a double dot system using a novel, numerically exact yet efficient technique, based on finite-element methods. Specifically, we evaluate the exchange coupling...
Frederiksen, Thomas, Paulsson, Magnus, Brandbyge, Mads, Jauho, Antti-Pekka
We describe a first-principles method for calculating electronic structure, vibrational modes and frequencies, electron-phonon couplings, and inelastic electron transport properties of an...
Electronic transport in Si nanowires: Role of bulk and surface disorder (2006)
Markussen, Troels, Rurali, Riccardo, Brandbyge, Mads, Jauho, Antti-Pekka
We calculate the resistance and mean free path in long metallic and semiconducting silicon nanowires (SiNWs) using two different numerical approaches: A real space Kubo method and a recursive Green's...
Quantum computing via defect states in two-dimensional anti-dot lattices (2005)
Flindt, Christian, Mortensen, Niels Asger, Jauho, Antti-Pekka
We propose a new structure suitable for quantum computing in a solid state environment: designed defect states in antidot lattices superimposed on a two-dimensional electron gas at a semiconductor...
Noise and Bistabilities in Quantum Shuttles (2005)
Flindt, Christian, Novotny, Tomas, Jauho, Antti-Pekka
We present a study of current fluctuations in two models proposed as quantum shuttles. Based on a numerical evaluation of the first three cumulants of the full counting statistics we have recently...
Current noise spectrum of a quantum shuttle (2004)
Flindt, Christian, Novotny, Tomas, Jauho, Antti-Pekka
We present a method for calculating the full current noise spectrum for the class of nano-electromechanical systems (NEMS) that can be described by a Markovian generalized master equation. As a...
Modeling of quantum electromechanical systems (2004)
Jauho, Antti-Pekka, Novotny, Tomas, Donarini, Andrea, Flindt, Christian
We discuss methods for numerically solving the generalized Master equation GME which governs the time-evolution of the reduced density matrix of a mechanically movable mesoscopic device in a...
Modeling of inelastic transport in one-dimensional metallic atomic wires (2004)
Frederiksen, Thomas, Brandbyge, Mads, Lorente, Nicolas, Jauho, Antti-Pekka
Inelastic effects in electron transport through nano-sized devices are addressed with a method based on nonequilibrium Green's functions (NEGF) and perturbation theory to infinite order in the...
Inelastic scattering and local heating in atomic gold wires (2004)
Frederiksen, Thomas, Brandbyge, Mads, Lorente, Nicolas, Jauho, Antti-Pekka
We present a method for including inelastic scattering in a first-principles density-functional computational scheme for molecular electronics. As an application, we study two geometries of four-atom...
Full counting statistics of nano-electromechanical systems (2004)
Flindt, Christian, Novotny, Tomas, Jauho, Antti-Pekka
We develop a theory for the full counting statistics (FCS) for a class of nanoelectromechanical systems (NEMS), describable by a Markovian generalized master equation. The theory is applied to two...
Current noise in a vibrating quantum dot array (2004)
Flindt, Christian, Novotny, Tomas, Jauho, Antti-Pekka
We develop methods for calculating the zero-frequency noise for quantum shuttles, i.e. nanoelectromechanical devices where the mechanical motion is quantized. As a model system we consider a...
Shot Noise of a Quantum Shuttle (2004)
Novotny, Tomas, Donarini, Andrea, Flindt, Christian, Jauho, Antti-Pekka
We formulate a theory for shot noise in quantum nanoelectromechanical systems. As a specific example, the theory is applied to a quantum shuttle, and the zero-frequency noise, measured by the Fano...
Shuttle instabilities: semiclassical phase analysis (2004)
Donarini, Andrea, Jauho, Antti-Pekka
We present a semiclassical analysis of the instability of an electron shuttle composed of three quantum dots: two are fixed and coupled via leads to electron resevoirs at different chemical...
Quantum theory of shuttling instability in a movable quantum dot array (2004)
Donarini, Andrea, Novotny, Tomas, Jauho, Antti-Pekka
We study the shuttling instability in an array of three quantum dots the central one of which is movable. We extend the results by Armour and MacKinnon on this problem to a broader parameter regime....
Quantum Shuttle in Phase Space (2003)
Novotny, Tomas, Donarini, Andrea, Jauho, Antti-Pekka
We present a quantum theory of the shuttle instability in electronic transport through a nanostructure with a mechanical degree of freedom. A phase space formulation in terms of the Wigner function...
Nonequilibrium Green function modelling of transport in mesoscopic systems (2002)
A generalized Landauer formula, derived with the methods due to Keldysh, and Baym and Kadanoff, is gaining widespread use in the modeling of transport in a large number of different mesoscopic...
Sign-reversal of drag in bilayer systems with in-plane periodic potential modulation (2002)
Alkauskas, Audrius, Flensberg, Karsten, Hu, Ben Yu-Kuang, Jauho, Antti-Pekka
We develop a theory for describing frictional drag in bilayer systems with in-plane periodic potential modulations, and use it to investigate the drag between bilayer systems in which one of the...
On the Applicability of Miniband Transport in Semiconductor Superlattices (2002)
Wacker, Andreas, Jauho, Antti-Pekka
Electrical transport in semiconductor superlattices is often described by a minnband model, where the electrons perform a quasiclassical motion. Although this model is assumed to be valid in the...
Mesoscopic fluctuations of Coulomb drag between quasi-ballistic 1D-wires (2001)
Mortensen, Niels Asger, Flensberg, Karsten, Jauho, Antti-Pekka
Quasiballistic 1D quantum wires are known to have a conductance of the order of 2e^2/h, with small sample-to-sample fluctuations. We present a study of the transconductance G_12 of two...
Coulomb drag in the mesoscopic regime (2001)
Mortensen, Niels Asger, Flensberg, Karsten, Jauho, Antti-Pekka
We present a theory for Coulomb drag between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and...
Coulomb drag in phase-coherent mesoscopic structures - Numerical study of disordered 1D-wires (2001)
Mortensen, Niels Asger, Flensberg, Karsten, Jauho, Antti-Pekka
We study Coulomb drag between two parallel disordered mesoscopic 1D-wires. By numerical ensemble averaging we calculate the statistical properties of the transconductance G_21 including its...
Coulomb Drag in Coherent Mesoscopic Systems (2001)
Flensberg, Karsten, Jauho, Antti-Pekka, Mortensen, Niels Asgar
Coulomb Drag in Coherent Mesoscopic Systems (2000)
Mortensen, Niels Asger, Flensberg, Karsten, Jauho, Antti-Pekka
We present a theory for Coulomb drag between two mesoscopic systems. Our formalism expresses the drag in terms of scattering matrices and wave functions, and its range of validity covers both...
Mortensen, Niels Asger, Jauho, Antti-Pekka, Flensberg, Karsten
An inherent difficulty in studying mesoscopic effects in semiconductor--superconductor hybrid structures is the large Schottky barrier which often forms at the interface. A large technological effort...
Dephasing in semiconductor-superconductor structures by coupling to a voltage probe (1999)
Mortensen, Niels Asger, Jauho, Antti-Pekka, Flensberg, Karsten
We study dephasing in semiconductor-superconductor structures caused by coupling to a voltage probe. We consider structures where the semiconductor consists of two scattering regions between which...
Contact resistance of quantum tubes (1999)
Mortensen, Niels Asger, Johnsen, Kristinn, Jauho, Antti-Pekka, Flensberg, Karsten
We consider the conductance of a quantum tube connected to a metallic contact. The number of angular momentum states that the tube can support depends on the strength of the radial confinement. We...
Quasienergy Spectroscopy of Excitons (1999)
Johnsen, Kristinn, Jauho, Antti-Pekka
We theoretically study nonlinear optics of excitons under intense THz irradiation. In particular, the linear near infrared absorption and resonantly enhanced nonlinear sideband generation are...
Conductance enhancement in quantum point contact-semiconductor-superconductor devices (1999)
Mortensen, Niels Asger, Jauho, Antti-Pekka, Flensberg, Karsten, Schomerus, Henning
We present numerical calculations of the conductance of an interface between a phase-coherent two-dimensional electron gas and a superconductor with a quantum point contact in the normal region....
Conductance enhancement in quantum-point-contact semiconductor-superconductor devices (1999)
Mortensen, Niels Asher, Jauho, Antti-Pekka, Flensberg, Karsten, Schomerus, Henning
We present numerical calculations of the conductance of an interface between a phase-coherent two-dimensional electron gas and a superconductor with a quantum point contact in the normal region....
Conductance enhancement in quantum-point-contact semiconductor-superconductor devices (1999)
Mortensen, Niels Asher, Jauho, Antti-Pekka, Flensberg, Karsten, Schomerus, Henning
We present numerical calculations of the conductance of an interface between a phase-coherent two-dimensional electron gas and a superconductor with a quantum point contact in the normal region....
Conductance enhancement in quantum-point-contact semiconductor-superconductor devices . (1999)
Mortensen, Niels Asher, Jauho, Antti-Pekka, Flensberg, Karsten, Schomerus, Henning
We present numerical calculations of the conductance of an interface between a phase-coherent two-dimensional electron gas and a superconductor with a quantum point contact in the normal region....
Current responsivity of semiconductor superlattice THz-photon detectors (1998)
Ignatov, Anatoly A., Jauho, Antti-Pekka
The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector...
Angle dependence of Andreev scattering at semiconductor-superconductor interfaces (1998)
Mortensen, Niels Asger, Flensberg, Karsten, Jauho, Antti-Pekka
We study the angle dependence of the Andreev scattering at a semiconductor-superconductor interface, generalizing the one-dimensional theory of Blonder, Tinkham and Klapwijk. An increase of the...
Quantum transport: The link between standard approaches in superlattices (1997)
Wacker, Andreas, Jauho, Antti-Pekka
Theories describing electrical transport in semiconductor superlattices can essentially be divided in three disjoint categories: i) transport in a miniband; ii) hopping between Wannier-Stark ladders;...
Wacker, Andreas, Jauho, Antti-Pekka, Zeuner, Stefan, Allen, S. James
We report a combined theoretical and experimental study of electrical transport in weakly-coupled doped superlattices. Our calculations exhibit negative differential conductivity at sufficiently high...
Johnsen, Kristinn, Jauho, Antti-Pekka
We theoretically study the effect of THz radiation on the linear optical absorption spectra of semiconductor structures. A general theoretical framework, based on non-equilibrium Green functions, is...
Quantum Transport in Ultrasmall Devices: NATO ASI. (1997)
Ferry, David K., Grubin, Harold L., Jacoboni, Carlo, Jauho, Antti-Pekka
As a method of training new young people in the approaches that have been used, a NATO Advanced Study Institute was held at 11 Ciocco, Lucca, Italy, during 17-30 July 1994, on the subject of "Quantum...
Impurity bands and sequential resonant tunneling in the presence of terahertz fields (1996)
Wacker, Andreas, Jauho, Antti-Pekka, Zeuner, Stefan, Allen, S. James
A theoretical and experimental study of transport in a low doped multiple quantum well structure shows that impurity bands are essential in understanding the electronic transport both with and...
Wacker, Andreas, Jauho, Antti-Pekka
A microscopic calculation of the perpendicular current in doped multiple quantum wells is presented. Interface roughness is shown to affect the resonant transitions as well as to cause a nonresonant...
Microscopic modelling of perpendicular electronic transport in doped multiple quantum wells (1996)
Wacker, Andreas, Jauho, Antti-Pekka
We present a microscopic calculation of transport in strongly doped superlattices where domain formation is likely to occur. Our theoretical method is based on a current formula involving the...
Rotvig, Jon, Jauho, Antti-Pekka, Smith, Henrik
We present an analytical study of one-dimensional semiconductor superlattices in external electric fields, which may be time-dependent. A number of general results for the (quasi)energies and...
Linear response theory of Coulomb drag in coupled electron systems (1995)
Flensberg, Karsten, Hu, Ben Yu-Kuang, Jauho, Antti-Pekka, Kinaret, Jari M.
We report a fully microscopic theory for transconductivity, or, equivalently, momentum transfer rate, of Coulomb coupled electron systems. We use the Kubo linear response formalism, and our main...
Time-dependent transport in interacting and non-interacting mesoscopic systems (1994)
Jauho, Antti-Pekka, Wingreen, Ned S., Meir, Yigal
We consider a mesoscopic region coupled to two leads under the influence of external time-dependent voltages. The time dependence is coupled to source and drain contacts, the gates controlling the...
Time-Dependent Transport through a Mesoscopic Structure (1993)
Wingreen, Ned S., Jauho, Antti-Pekka, Meir, Yigal
We present a general formulation of the nonlinear, time-dependent current through a small interacting region, where electron energies are changed by time-dependent voltages. An exact solution is...
Coulomb drag between two-dimensional electron systems (1992)
Jauho, Antti-Pekka, Smith, Henrik
The Coulomb contribution to the temperature-dependent rate of momentum transfer, $1/\tau_D$, between two electron systems in parallel layers is determined by setting up two coupled Boltzmann...