Den 18. og sidste Landmandsforsamling i Odense år 1900.

I 1845 havde Det Kongelige Danske Landhusholdningsselskab taget initiativ til et Landmandsforsamlingsmøde, hvor landbrugets bedste mænd skulle mødes til en tvangfri drøftelse af spørgsmål af betydning for erhvervet. I 1900 blev så det 18. møde arrangeret til at finde sted i Odense.Esben Hedegaard, der var museumsinspektør ved Odense Bys Museer, senere museumschef for Svendborg Museum har fundet et fantastisk stort og hidtil overset materiale om dette møde, der skulle blive det sidste af sin art.Udover kronprinsen (Frederik 8.)  kom der over 100.000 mennesker til dette møde, selv om det regnede næsten alle dage og yderligere 2.000 store dyr og 2.800 stykker fjerkræ samt utallige nye maskiner og redskaber.Mødet kostede en formue, og Esben Hedegaard er ikke i tvivl om, hvorfor det blev iscenesat. Han mener, at det i høj grad var de stadig herskende kredses forsøg på at sikre sig opbakning.

Interferometric Single-Shot Parity Measurement in an InAs-Al Hybrid Device

The fusion of non-Abelian anyons or topological defects is a fundamental operation in measurement-only topological quantum computation. In topological superconductors, this operation amounts to a determination of the shared fermion parity of Majorana zero modes. As a step towards this, we implement a single-shot interferometric measurement of fermion parity in indium arsenide-aluminum heterostructures with a gate-defined nanowire. The interferometer is formed by tunnel-coupling the proximitized nanowire to quantum dots. The nanowire causes a state-dependent shift of these quantum dots' quantum capacitance of up to 1 fF. Our quantum capacitance measurements show flux h/2e-periodic bimodality with a signal-to-noise ratio of 1 in 3.7 $\mu$s at optimal flux values. From the time traces of the quantum capacitance measurements, we extract a dwell time in the two associated states that is longer than 1 ms at in-plane magnetic fields of approximately 2 T. These results are consistent with a measurement of the fermion parity encoded in a pair of Majorana zero modes that are separated by approximately 3 $\mu$m and subjected to a low rate of poisoning by non-equilibrium quasiparticles. The large capacitance shift and long poisoning time enable a parity measurement error probability of 1%.Comment: Added data on a second measurement of device A and a measurement of device B, expanded discussion of a trivial scenario. Refs added, author list update

Terahertz Optical Rectification and Second-Harmonic Generation at the Surface of Nonlinear Crystals

International audienc

THz and SH Generation in reflection at the surface of a dielectric crystal using a double pulse laser excitation

National audienceWe present an original THz generation/detection configuration using an autocorrelation technique. By second-order nonlinear effects, THz and SH signals are generated in reflection at the surface of a dielectric crystal and detected simultaneously. This technic, by detecting weak and broadband THz signals, could be useful for surface spectroscopy