Milena Grifoni

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Room-temperature single-electron transistors are realized within individual metallic single-wall carbon nanotube molecules. The devices feature a short (down to approximately 20 nanometers) nanotube section that is created by inducing local barriers into the tube with an atomic force microscope. Coulomb charging is observed at room temperature, with an(More)
A contemporary review on the behavior of driven tunneling in quantum systems is presented. Diverse phenomena, such as control of tunneling, higher harmonic generation, manipulation of the population dynamics and the interplay between the driven tunneling dynamics and dissipative effects are discussed. In the presence of strong driving fields or ultrafast(More)
A study of the dynamics of a tunneling particle in a driven bistable potential which is moderately to strongly coupled to a bath is presented. Upon restricting the system dynamics to the Hilbert space spanned by the M lowest energy eigenstates of the bare static potential, a set of coupled non-Markovian master equations for the diagonal elements of the(More)
We investigate directed motion in nonadiabatically rocked ratchet systems sustaining few bands below the barrier. Upon restricting the dynamics to the lowest M bands, the total system-plus-bath Hamiltonian is mapped onto a discrete tight-binding model containing all the information both on the intrawell and interwell tunneling motion. A closed form for the(More)
We present a microscopic theory for interacting graphene armchair nanoribbon quantum dots. Long-range interaction processes are responsible for Coulomb blockade and spin-charge separation. Short-range ones, arising from the underlying honeycomb lattice of graphene smear the spin-charge separation and induce exchange correlations between bulk electrons(More)
Daniel R. Schmid,1 Sergey Smirnov,2 Magdalena Margańska,2 Alois Dirnaichner,1,2 Peter L. Stiller,1 Milena Grifoni,2 Andreas K. Hüttel,1,* and Christoph Strunk1,† 1Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany 2Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany(More)
We have measured a quantum ratchet effect for vortices moving in a quasi-one-dimensional Josephson junction array. In this solid-state device the shape of the vortex potential energy, and consequently the band structure, can be accurately designed. This band structure determines the presence or absence of the quantum ratchet effect. In particular,(More)
Subhadeep Datta,1 Shidong Wang,2 Carmen Tilmaciu,3 Emmanuel Flahaut,4 Laëtitia Marty,1 Milena Grifoni,5 and Wolfgang Wernsdorfer1 1Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9, France 2Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA 3Université de Toulouse,(More)
We investigate quantum Brownian motion in adiabatically rocked ratchet systems. Above a crossover temperature Tc tunneling events are rare, yet they already substantially enhance the classical particle current. Below Tc, quantum tunneling prevails and the classical predictions grossly underestimate the transport. Upon approaching T ­ 0 the quantum current(More)