Nonlinear conductance of nanowires - A signature of Luttinger liquid effects?

We analyze recent measurements of the room temperature current-voltage characteristics of gold nanowires, whose zero current conductance is quantized in units of $2e^2/h$. A faster than linear increase of current with voltage was observed at low voltages beginning from $V_c=0.1$V. We analyze the nonlinear behavior in terms of a dynamic Coulomb blockade of conducting modes and show that it may be explained as a Luttinger-liquid effect.Comment: 13 pages, latex with supplied stylefile, 3 figures in eps format, submitted to Superlattices and Microstructure

Phase-Controlled Force and Magnetization Oscillations in Superconducting Ballistic Nanowires

The emergence of superconductivity-induced phase-controlled forces in the (0.01-0.1) nN range, and of magnetization oscillations, in nanowire junctions, is discussed. A giant magnetic response to applied weak magnetic fields, is predicted in the ballistic Josephson junction formed by a superconducting tip and a surface, bridged by a normal metal nanowire where Andreev states form.Comment: 5 pages, 3 figure

Landscape perception: linking physical monitoring data to perceived landscape properties

Changes in the landscape affect not only people's well-being but also how people perceive and use the landscape. An increasing number of policies have highlighted the importance of conserving a landscape's recreational and aesthetical values. This study develops and evaluates a model that links people's perceptions of a mountain landscape to physical monitoring data. Using a questionnaire, we revealed how respondents working with the Swedish mountains characterise the Magnificent Mountain landscape (as defined by Swedish policy objectives) and translated these characteristics into data from the National Inventory of Landscapes in Sweden (NILS). We found 14 potential indicators that could be derived from the existing NILS physical monitoring data and which could be used to monitor changes in the landscape values as perceived by people. Based on the results, we suggest how to simultaneously utilise field sampling of physical data and field photos to provide temporal information about landscape perception

Persistent current in a one-dimensional ring of fractionally charged "exclusons''

The Aharonov-Bohm effect in a one-dimensional (1D) ring containing a gas of fractionally charged excitations is considered. It is shown that the low temperature behavior of the system is identical to that of free electrons with (integer) charge $e$. This is a direct consequence of the fact that the total charge in the ring is quantized in units of the electron charge. Anomalous oscillations of the persistent current amplitude with temperature are predicted to occur as a direct manifistation of the fractional nature of the quasiparticle charge. A 1D conducting ring with gate induced periodical potential is discussed as a possible set-up for an experimental observation of the predicted phenomenon.Comment: 4 pages, RevTex, uuencoded figure

Effect of Charge Fluctuations on the Persistent Current through a Quantum Dot

We study coherent charge transfer between an Aharonov-Bohm ring and a side-attached quantum dot. The charge fluctuation between the two sub-structures is shown to give rise to algebraic suppression of the persistent current circulating the ring as the size of the ring becomes relatively large. The charge fluctuation at resonance provides transition between the diamagnetic and the paramagnetic states. Universal scaling, crossover behavior of the persistent current from a continuous to a discrete energy limit in the ring is also discussed.Comment: 5 pages, 4 figure

Aharonov-Bohm Oscillations in a One-Dimensional Wigner Crystal-Ring

We calculate the magnetic moment (`persistent current') in a strongly correlated electron system --- a Wigner crystal --- in a one-dimensional ballistic ring. The flux and temperature dependence of the persistent current in a perfect ring is shown to be essentially the same as for a system of non-interacting electrons. In contrast, by incorporating into the ring geometry a tunnel barrier that pins the Wigner crystal, the current is suppressed and its temperature dependence is drastically changed. The competition between two temperature effects --- the reduced barrier height for macroscopic tunneling and loss of quantum coherence --- may result in a sharp peak in the temperature dependence. The character of the macroscopic quantum tunneling of a Wigner crystal ring is dictated by the strength of pinning. At strong pinning the tunneling of a rigid Wigner crystal chain is highly inhomogeneous, and the persistent current has a well-defined peak at $T\sim 0.5\ \hbar s/L$ independent of the barrier height ($s$ is the sound velocity of the Wigner crystal, $L$ is the length of the ring). In the weak pinning regime, the Wigner crystal tunnels through the barrier as a whole and if $V_p>T_0$ the effect of the barrier is to suppress the current amplitude and to shift the crossover temperature from $T_0$ to $T^*\simeq \sqrt{V_{p}T_{0}}$. ($V_{p}$ is the amplitude of the pinning potential, $T_{0} =\hbar v_{F}/L ,\; v_{F}\sim \hbar/ma$ is the drift velocity of a Wigner crystal ring with lattice spacing $a$). For very weak pinning, $V_p\ll T_0$, the influence of the barrier on the persistent current of a Wigner crystal ring is negligibly small.Comment: 30 pages, RevTeX, 2 figures available on reques

Education for optimized Life Cycle Management : The Project e-CIRP and its insights into embedding circular economy aspects to product design via teaching

Publisher Copyright: © The Authors, published by EDP Sciences.The integration of circular economy-based life cycle management (LCM) into product design and optimisation is essential for the transformation towards a circular economy (CE). However, companies often lack the expertise to adapt life-cycle design (LCD) thinking in their business operations and are in need of respective capacity building. To close this apparent gap is the aim of the project e-CirP (Embedding Circular Economy into Product Design and Optimization) where LUT University, Fraunhofer, Technical University of Denmark, University of Padova, Delft University of Technology, University of Helsinki and Metso Outotec have worked together to develop a program that allows Master students across Europe to learn how to integrate CE and Life Cycle Thinking principles into product design by analysing real industrial cases. In the project, modern pedagogical approaches have been applied. A modular training package covering general circular economy aspects, as well as detailed value chain perspectives, has been created. Next to the content-related aspects, a great focus was also on the support of so-called soft-skills development, e.g. through international student cooperation on case studies. The paper presents the perspective of participating students as well as the cooperating companies that supplied the industry cases to allow an overview of opportunities and challenges.Peer reviewe