Passage-time distributions from a spin-boson detector model

The passage-time distribution for a spread-out quantum particle to traverse a specific region is calculated using a detailed quantum model for the detector involved. That model, developed and investigated in earlier works, is based on the detected particle's enhancement of the coupling between a collection of spins (in a metastable state) and their environment. We treat the continuum limit of the model, under the assumption of the Markov property, and calculate the particle state immediately after the first detection. An explicit example with 15 boson modes shows excellent agreement between the discrete model and the continuum limit. Analytical expressions for the passage-time distribution as well as numerical examples are presented. The precision of the measurement scheme is estimated and its optimization discussed. For slow particles, the precision goes like $E^{-3/4}$, which improves previous $E^{-1}$ estimates, obtained with a quantum clock model.Comment: 11 pages, 6 figures; minor changes, references corrected; accepted for publication in Phys. Rev.

Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022

Themenschwerpunkte: 1. Modell- und Feldversuche 2. Digitalisierung und künstliche Intelligenz in der Geotechnik 3. Nationale und internationale Großprojekte 4. Normung und Rechtliche

Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022

Themenschwerpunkte: 1. Modell- und Feldversuche 2. Digitalisierung und künstliche Intelligenz in der Geotechnik 3. Nationale und internationale Großprojekte 4. Normung und Rechtliche

Ankunfts- und Durchflugszeiten von einem Spin-Boson Detektor-Modell

Die vorliegende Arbeit verfolgt ein zweifaches Ziel: Einerseits befasst sie sich mit der Behandlung von Zeitobservablen in der Quantenmechanik. Insbesondere beschäftigt sie sich mit der Anwendung eines konkreten Spin-Boson Detektor-Modells auf Ankunfts- und Durchflugszeiten. Andererseits untersucht sie die Möglichkeit, die Quantensprung-Methode auf ein Modell außerhalb ihres ursprünglichen quantenoptischen Rahmens zu erweitern. Sie untersucht auch mittels numerischer Beispiele, ob die Quantensprung-Methode, die ein Kontinuum von Bad-Moden verwendet, eine gute Approximation an Situationen verspricht, in denen man eigentlich mit einer Anzahl diskreter Bad-Moden konfrontiert ist

Synthesis of Bifunctional Boron-Lewis Acids - Thorough Investigation of the Adduct Formation with Pyrimidine

Rudlof J, Glodde T, Mix A, Neumann B, Stammler H-G, Mitzel NW. Synthesis of Bifunctional Boron-Lewis Acids - Thorough Investigation of the Adduct Formation with Pyrimidine. European Journal of Inorganic Chemistry . 2022: e202100842.Three bifunctional boron-Lewis acids based on a 1,2-diethynylbenzene backbone were synthesized using a tin-boron exchange protocol in good to very good yields. Complexation experiments with pyrimidine were thoroughly investigated using the example of 1,2-bis(benzo[d][1,3,2]dioxaborol-2-ylethynyl)benzene (3) in solution, in the solid phase and by quantum-chemical calculations. Two adducts were structurally investigated by X-ray diffraction experiments. DOSY-/VT-NMR experiments gave insight into the dynamic behaviour of the synthesized poly-Lewis acids with pyrimidine

Mapping the upper mantle: three-dimensional modeling of Earth structure by inversion of seismic waveforms.

A majority of current disease-modifying therapeutic approaches for age-related neurodegenerative diseases target their characteristic proteopathic lesions (α-synuclein, Tau, Aβ). To monitor such treatments, fluid biomarkers reflecting the underlying disease process are crucial. We found robust increases of neurofilament light chain (NfL) in CSF and blood in murine models of α-synucleinopathies, tauopathy, and β-amyloidosis. Blood and CSF NfL levels were strongly correlated, and NfL increases coincided with the onset and progression of the corresponding proteopathic lesions in brain. Experimental induction of α-synuclein lesions increased CSF and blood NfL levels, while blocking Aβ lesions attenuated the NfL increase. Consistently, we also found NfL increases in CSF and blood of human α-synucleinopathies, tauopathies, and Alzheimer's disease. Our results suggest that CSF and particularly blood NfL can serve as a reliable and easily accessible biomarker to monitor disease progression and treatment response in mouse models and potentially in human proteopathic neurodegenerative diseases

A gentle introduction to theory (for non-theoreticians)

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