In situ magnetoresistance measurements of ferromagnetic nanocontacts in the Lorentz transmission electron microscope

We report on in situ magnetoresistance measurements of a 30-nm-wide ferromagnetic nanocontact with simultaneous magnetic imaging in the Lorentz transmission electron microscope. The magnetoresistive measurements are correlated with the micromagnetic configuration of the sample. This allows us to assign characteristic features in the magnetoresistance curves to different magnetic configurations of the sample. From our experiments we can conclude that the micromagnetic configuration of the whole sample—not only the nanocontact region—has to be taken into account for the interpretation of magnetoresistive effects or hysteresis loops. Micromagnetic simulations were performed which confirm the experimental results

Distribution of discontinuous mudstone beds within wave-dominated shallow-marine deposits : Star Point Sandstone and Blackhawk Formation, Eastern Utah

Acknowledgements Funding for this study was provided from the Research Council of Norway through the Petromaks project 193059 and the FORCE Safari Project. The lidar data was collected by Julien Vallet and Samuel Pitiot of Helimap Systems SA. Riegl LMS GmbH is acknowledged for software support. The first author would like to thank Oliver Severin Tynes for assistance in the field. Tore Grane Klausen and Gijs Allard Henstra are thanked for invaluable discussions. The authors would also like to thank Janok Bhattacharya, Cornel Olariu and one anonymous revier for their insightful comments which improved this paper, and Frances Witehurst for his editorial comments.Peer reviewedPostprin

Sedimentology and reservoir properties of tabular and erosive offshore transition deposits in wave-dominated, shallow-marine strata : Book cliffs, USA

Acknowledgements and Funding Funding for this study was provided from the Research Council of Norway (Petromaks project 193059) and the FORCE Safari project. The helicopter-LiDAR data was collected by J. Valet and S. Pitiot of Helimap System SA. Riegl LMS GmbH is acknowledged for software support for the outcrop models, and ROXAR is acknowledged for use of their RMS reservoir modelling package. A. Rittersbacher is acknowledged for processing the heli-LiDAR model. The first author would like to thank O. S. Mulelid-Tynes and G. Henstra for assistance in the field and for valuable discussions. G. Hampson is thanked for insightful comments that significantly improved this manuscriptPeer reviewedPostprin

Spin-dependent shot noise enhancement in a quantum dot

The spin-dependent dynamical blockade was investigated in a lateral quantum dot in a magnetic field. Spin-polarized edge channels in the two-dimensional leads and the spatial distribution of Landau orbitals in the dot modulate the tunnel coupling of the quantum dot level spectrum. In a measurement of the electron shot noise we observe a pattern of super-Poissonian noise which is correlated to the spin-dependent competition between different transport channels

Continuous development of the postgraduate course GEOV360 – Advanced Clastic Sedimentology: Years 2017 to 2021

This is a report in the course UPED620 – Basic module in university pedagogics, where I describe the changes I have done to the course GEOV360 – Advanced Clastic Sedimentology over the last five years. These changes include restructuring of the teaching to include much more student active learning, redefined course goals, an assessment strategy that is strongly aligned with the course goals, and a comprehensive student evaluation program. The goal of these changes has been to improve student learning and knowledge retention of the geological skills taught in the course, and to give the students experience in data interpretation, handling uncertainty, teamwork and giving presentations. The purpose of this report is to share insights with other educators who may be able to benefit from my experiences

High-order cumulants in the counting statistics of asymmetric quantum dots

Measurements of single electron tunneling through a quantum dot using a quantum point contact as charge detector have been performed for very long time traces with very large event counts. This large statistical basis is used for a detailed examination of the counting statistics for varying symmetry of the quantum dot system. From the measured statistics we extract high order cumulants describing the distribution. Oscillations of the high order cumulants are observed when varying the symmetry. We compare this behavior to the observed oscillation in time dependence and show that the variation of both system variables lead to the same kind of oscillating response.Comment: 3 page

Bosonic behavior of excitons and screening: a consistent calculation

Excitons have recently been shown to deviate from pure bosons at densities a hundred times smaller than the Mott density. The corresponding calculations relied on the unscreened excitonic ground state wavefunction. A consistent inclusion of screening, by use of the fundamental eigenfunction of the Hulth\'{e}n potential, vindicates this approximation.Comment: 4 pages, 1 figur

Quantum confinement effects in Si/Ge heterostructures with spatially ordered arrays of self-assembled quantum dots

Magnetotunneling spectroscopy was employed to probe the confinement in vertical Si/Ge double-barrier resonant tunneling diodes with regularly distributed Ge quantum dots. Their current-voltage characteristics reveal a step-like behavior in the vicinity of zero bias, indicating resonant tunneling of heavy-holes via three-dimensionally confined unoccupied hole states in Ge quantum dots. Assuming parabolic confinement we extract the strength of the confinement potential of quantum dots.Comment: 4 pages, 3 figure

First African thylacocephalans from the Famennian of Morocco and their role in Late Devonian food webs

Thylacocephalans are enigmatic arthropods with an erratic Palaeozoic and Mesozoic fossil record. In many of the few localities where they occur, they are quite abundant. This also holds true for the Famennian Thylacocephalan Layer in the Maider (eastern Anti-Atlas of Morocco), a small epicontinental basin hosting some strata with taphonomic properties of a conservation deposit yielding exceptionally preserved gnathostomes and non-vertebrates. In a thin argillaceous interval in the earliest middle Famennian, thylacocephalans occur in such great numbers that they became eponyms of this unit. Therein, we discovered a new taxon of thylacocephalans, Concavicaris submarinus sp. nov., which represent the oldest records of thylacocephalans from Africa. In the CT-imagery, the holotype of Concavicaris submarinus sp. nov. revealed anatomical details including its eyes, appendages and other soft parts. Sedimentary facies and faunal composition of the Thylacocephalan Layer suggest that these animals populated the water column above the low-oxygen sea floor. Thus, thylacocephalans likely represented an important component of the diet of chondrichthyans and placoderms, which are quite common as well. The abundance of thylacocephalans in other conservation deposits like the Cleveland Shale (USA) and the Gogo Formation (Australia) underline their pivotal role in Late Devonian pelagic food webs

High cumulants in the counting statistics measured for a quantum dot

We report on measurements of single electron tunneling through a quantum dot using a quantum point contact as non-invasive charge detector with fast time response. We elaborate on the unambiguous identification of individual tunneling events and determine the distribution of transferred charges, the so-called full counting statistics. We discuss our data analysis, including the error estimates of the measurement, and show that the quality of our experimental results is sufficiently high to extract cumulants of the distribution up to the 20th order for short times.Comment: 4 pages, 3 figures, Contribution to EP2DS18-MSS14, Kobe, Japan, July 200