Nonlinear thermoelectric response due to energy-dependent transport properties of a quantum dot

Quantum dots are useful model systems for studying quantum thermoelectric behavior because of their highly energy-dependent electron transport properties, which are tunable by electrostatic gating. As a result of this strong energy dependence, the thermoelectric response of quantum dots is expected to be nonlinear with respect to an applied thermal bias. However, until now this effect has been challenging to observe because, first, it is experimentally difficult to apply a sufficiently large thermal bias at the nanoscale and, second, it is difficult to distinguish thermal bias effects from purely temperature-dependent effects due to overall heating of a device. Here we take advantage of a novel thermal biasing technique and demonstrate a nonlinear thermoelectric response in a quantum dot which is defined in a heterostructured semiconductor nanowire. We also show that a theoretical model based on the Master equations fully explains the observed nonlinear thermoelectric response given the energy-dependent transport properties of the quantum dot.Comment: Cite as: A. Svilans, et al., Physica E (2015), http://dx.doi.org/10.1016/j.physe.2015.10.00

Pengaruh alokasi anggaran sektor pertanian dan industri terhadap PDRB di Kabupaten Kerinci

  This study aims to analyze the development of the agricultural and industrial sector budgets and analyze the effect of the farming and industrial sector budget allocations on the GRDP in the Kerinci district. The analytical method used is multiple linear regression with Ordinary Least Square (OLS). This study indicates that the development of the industrial sector budget in Kerinci Regency for the 2010 to 2020 period has fluctuated with an average growth of Rp. 36,920,377,491 per year and the average industrial sector budget in Kerinci Regency for the 2010 to 2020 period is Rp. 8,154,752,012 per year. And the results of the analysis of factors that affect GRDP in Kerinci Regency, simultaneously the agricultural and industrial sector budget variables have a significant effect on GRDP, and partially the industrial sector budget has a significant impact. The farm sector budget has no significant effect.  Keywords: GRDP, Agriculture sector budget, Industry sector budget

A quantum-dot heat engine operating close to the thermodynamic efficiency limits

Cyclical heat engines are a paradigm of classical thermodynamics, but are impractical for miniaturization because they rely on moving parts. A more recent concept is particle-exchange (PE) heat engines, which uses energy filtering to control a thermally driven particle flow between two heat reservoirs. As they do not require moving parts and can be realized in solid-state materials, they are suitable for low-power applications and miniaturization. It was predicted that PE engines could reach the same thermodynamically ideal efficiency limits as those accessible to cyclical engines, but this prediction has not been verified experimentally. Here, we demonstrate a PE heat engine based on a quantum dot (QD) embedded into a semiconductor nanowire. We directly measure the engine's steady-state electric power output and combine it with the calculated electronic heat flow to determine the electronic efficiency $\eta$. We find that at the maximum power conditions, $\eta$ is in agreement with the Curzon-Ahlborn efficiency and that the overall maximum $\eta$ is in excess of 70$\%$ of the Carnot efficiency while maintaining a finite power output. Our results demonstrate that thermoelectric power conversion can, in principle, be achieved close to the thermodynamic limits, with direct relevance for future hot-carrier photovoltaics, on-chip coolers or energy harvesters for quantum technologies

Economic Integration

The results of international trade have generated a set of both winners and losers. On one side we have the big companies and big producers that stand out and on the other hand, there is a sector that has been affected such as groups of peasants, rural communities, cooperatives, amongst others that live in the poor southern countries. Therefore, the objective of this research article is the search and the design of mechanisms that will counteract the flaws of the current systems, and that will translate into social policies to give a solution to the more unprotected people. Fair trade is an alternative that is heading towards practices of a more social and solidary economy and through these mechanisms, that are funded in

Thermoelectric characterization of the Kondo resonance in nanowire quantum dots

We experimentally verify hitherto untested theoretical predictions about the thermoelectric properties of Kondo correlated quantum dots (QDs). The specific conditions required for this study are obtained by using QDs epitaxially grown in nanowires, combined with a recently developed method for controlling and measuring temperature differences at the nanoscale. This makes it possible to obtain data of very high quality both below and above the Kondo temperature, and allows a quantitative comparison with theoretical predictions. Specifically, we verify that Kondo correlations can induce a polarity change of the thermoelectric current, which can be reversed either by increasing the temperature or by applying a magnetic field

Is there a Common European Business Cycle? New Insights from a Frequency Domain Analysis

To assess the synchronization of business cycles in Europe we extract the cyclical component of industrial production in five European countries using the filter of Baxter and King (1999). The hypothesis of a joint business cycle is tested by using the frequency domain common cycle test suggested by Breitung and Candelon (2000). The common cycle hypothesis is clearly rejected for U.K. data whereas some weak evidence for a joint cyclical pattern is found for France, The Netherlands, Austria and Germany. Zusammenfassung Gibt es einen gemeinsamen europäischen Konjunkturzyklus? Neue Erkenntnisse durch eine Spektralanalyse Um die Synchronität der Konjunkturzyklen in Europa zu bewerten, wird die Zykluskomponente der Industrieproduktion in fünf europäischen Ländern identifiziert, indem der Baxter-King-Filter (1999) angewendet wird. Die Hypothese eines gemeinsamen Konjunkturzyklus wird durch einen Test auf einen gemeinsamen Zyklus im Frequenzbereich nach Breitung und Candelon (2000) überprüft. Ein gemeinsamer Konjunkturzyklus muss demnach für Großbritannien klar zurückgewiesen werden, wohingegen einige schwache Anzeichen für ein gemeinsames Konjunkturmuster für Frankreich, die Niederlande, Österreich und Deutschland gefunden werden konnten