Mach-Zehnder interferometry with periodic voltage pulses

We investigate a Mach-Zehnder interferometer driven by a time-dependent voltage. Motivated by recent experiments, we focus on a train of Lorentzian voltage pulses which we compare to a sinusoidal and a constant voltage. We discuss the visibilities of Aharonov-Bohm oscillations in the current and in the noise. For the current, we find a strikingly different behavior in the driven as compared to the static case for voltage pulses containing multiple charges. For pulses containing fractional charges, we find a universality at path-length differences equal to multiples of the spacing between the voltage pulses. These observations can be explained by the electronic energy distribution of the driven contact. In the noise oscillations, we find additional features which are characteristic to time-dependent transport. Finite electronic temperatures are found to have a qualitatively different influence on the current and the noise.Comment: Published version; 11 pages, 5 figure

Electron waiting times in coherent conductors are correlated

We evaluate the joint distributions of electron waiting times in coherent conductors described by scattering theory. Successive electron waiting times in a single-channel conductor are found to be correlated due to the fermionic statistics encoded in the many-body state. Our formalism allows us also to investigate the waiting times between charge transfer events in different outgoing channels. As an application we consider a quantum point contact in a chiral setup with one or both input channels biased by either a static or a time-dependent periodic voltage described by Floquet theory. The theoretical framework developed here can be applied to a variety of scattering problems and can in a straightforward manner be extended to joint distributions of several electron waiting times.Comment: 14 pages, 7 figure

Electron waiting times for the mesoscopic capacitor

We evaluate the distribution of waiting times between electrons emitted by a driven mesoscopic capacitor. Based on a wave packet approach we obtain analytic expressions for the electronic waiting time distribution and the joint distribution of subsequent waiting times. These semi-classical results are compared to a full quantum treatment based on Floquet scattering theory and good agreement is found in the appropriate parameter ranges. Our results provide an intuitive picture of the electronic emissions from the driven mesoscopic capacitor and may be tested in future experiments.Comment: 11 pages, 7 figures, invited contribution to special issue in Physica E on "Frontiers in quantum electronic transport - in memory of Markus B\"uttiker

On-demand entanglement generation using dynamic single-electron sources

We review our recent proposals for the on-demand generation of entangled few-electron states using dynamic single-electron sources. The generation of entanglement can be traced back to the single-electron entanglement produced by quantum point contacts acting as electronic beam splitters. The coherent partitioning of a single electron leads to entanglement between the two outgoing arms of the quantum point contact. We describe our various approaches for generating and certifying entanglement in dynamic electronic conductors and we quantify the influence of detrimental effects such as finite electronic temperatures and other dephasing mechanisms. The prospects for future experiments are discussed and possible avenues for further developments are identified.Comment: Published version, 11 pages, 7 figures, short review for focus issue on 'Single-electron control in solid-state devices'. in Phys. Status Solidi B (2016

The United States-European Union Open Aviation Area: The American Perspective

This paper presents a comprehensive analysis of current United States-European Union (U.S.-E.U.) aviation relations. Following a brief historical review, the proposed North-Atlantic Open Aviation Area is discussed. Specifically, the associated economic benefits are assessed, and the causes of the current deadlock in U.S.-E.U. negotiations are analyzed. Particular attention is paid to the interests and actions of U.S. stakeholders, most notably U.S. airlines, labor organizations, the Department of Transportation and Congress

Ready to Reform: How Popular Initiatives Can Be Successful

We study whether the number of signatures collected to qualify a popular initiative affects the probability of reforming the status quo. The initiative process is modeled as a sequential game under uncertainty: petitioners make an entry decision and collect signatures to qualify the initiative. Politicians decide about a political compromise - a counter proposal - after which petitioners have the option to withdraw the initiative before the vote. In equilibrium, politicians infer the initiative's popularity from the number of signatures and collection time. They more likely grant counter proposals to initiatives perceived as a threat to the status quo. To prove their success probability, petitioners sometimes have the incentive to collect more signatures than required for qualification. We test model predictions based on the data set of all Swiss constitutional initiatives at federal level between 1891 and 2010. Overall, we find supporting evidence for the model mechanisms. Reforms are most likely once a far-reaching counter proposal is issued such that the initiative is withdrawn. We find a significant effect of collecting more signatures than required on the probability of provoking a compromise