7 research outputs found
Carbon nanotubes for coherent spintronic devices
Carbon nanotubes bridge the molecular and crystalline quantum worlds, and
their extraordinary electronic, mechanical and optical properties have
attracted enormous attention from a broad scientific community. We review the
basic principles of fabricating spin-electronic devices based on individual,
electrically-gated carbon nanotubes, and present experimental efforts to
understand their electronic and nuclear spin degrees of freedom, which in the
future may enable quantum applications.Comment: 17 pages, 9 figures, submitted to Materials Toda
Vibration induced memory effects and switching in ac-driven molecular nanojunctions
We investigate bistability and memory effects in a molecular junction weakly
coupled to metallic leads with the latter being subject to an adiabatic
periodic change of the bias voltage. The system is described by a simple
Anderson-Holstein model and its dynamics is calculated via a master equation
approach. The controlled electrical switching between the many-body states of
the system is achieved due to polaron shift and Franck-Condon blockade in the
presence of strong electron-vibron interaction. Particular emphasis is given to
the role played by the excited vibronic states in the bistability and
hysteretic switching dynamics as a function of the voltage sweeping rates. In
general, both the occupation probabilities of the vibronic states and the
associated vibron energy show hysteretic behaviour for driving frequencies in a
range set by the minimum and maximum lifetimes of the system. The consequences
on the transport properties for various driving frequencies and in the limit of
DC-bias are also investigated.Comment: 15 pages, 20 figures, published versio