The list below includes some recent side-projects I worked on in my free time.
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Advanced Quantum Mechanics Summarized
A summary of the Quantum Field Theory course at the University of Geneva, taught by Prof. J. Jaeckel. The summary is based on the lecture notes and the book ‘Quantum Field Theory’ by Mark Srednicki.
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Constrained Multi-Body Physics Engine in C++: Theory & Implementation
Introducing my book Applied Mechanics Tutorials, within a short 45 min read, I give a first taste of C++ as a programming language and explain the fundamentals of contrained multi-body physics with all the mathematics needed to get started.
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Silent Speech Interface
Introducing my book Applied Mechanics Tutorials, within a short 45 min read, I give a first taste of C++ as a programming language and explain the fundamentals of contrained multi-body physics with all the mathematics needed to get started.
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Equations of Love as Sexual Selection
I took Steven Strogatz’ equations of love way too seriously, generalized them, and expanded them to a network of agents all capable of loving or hating each other, attracting or repulsing each other. These nonlinear dynamics are fascinating.
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Mode Sources and Monitors
Another BEAMZ FDTD package demo where we launch one guided waveguide mode, verify the launched power in a straight reference waveguide, and then reuse the same source/monitor setup for a simple width-step junction. The important quantities are the frequency-domain fields, the total flux through a monitor plane, and the modal amplitudes returned by the mode monitor.
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Topology Optimized 90° Bend
We use topology optimization to design a compact, efficient 90° photonic waveguide bend from first principles using BEAMZ. The optimizer maximizes bidirectional transmission through the bend by iteratively updating the refractive index distribution within a defined design region, using the adjoint method with a material penalty to control core material usage.
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Field-Dependent THz Transport Nonlinearities in Semiconductor Nano Structures
Quentin Wach,Michael T. Quick,Sabrine Ayari,Alexander W. Achtstein
The charge transport in semiconductor quantum dots and nanorods is studied theoretically, predicting strong field-dependent nonlinear mobility effects and intra-pulse gain. We studied the temperature- and size-sensitive mobility spectra, crucial for applications like 6G tech and nano electronics in general.
PCCP -
PONDER: Semantic Flashcards for 100x More Effective Spaced Repetition Using Knowledge Trees
Spaced repetition and apps utilizing it have had several fatal flaws with little to no progress in the past few decades. Cards accumulate that are redundant and easy yet performed on poorly even though the student has a good understanding of the subject overall. The algorithm often trains the student on topics he has already mastered. That is because measuring understanding is only done on a card-by-card basis. By generating semantic knowledge trees that relate flashcards to each other, creating a knoweldge graph with cards about a topic linked together, the algorithm can accurately estimate what topics the student understands well and which topics need to be studied further with unprecedented accuracy. This reduces the amount of flashcards needed to be studied by orders of magnitude. All of the code is open source and the app can be downloaded for free.
star 0 Download the free app: www.ponder.app 5% complete. -
Analog Computing: Neurons & Chaotic Attractors
A tiny analog computing unit on a PCB is built that allows to dynamically simulate the popular chaotic Lorenz system. This aims to give a short introduction to the power of analog computing.
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THz Response of Charge Carriers in Nanoparticles
Michael T. Quick,Quentin Wach,Nina Owschimikow,Alexander W. Achtstein
Presenting a new quantum mechanical theory that models the THz mobility of charge carriers in low-dimensional semiconductors, revealing nonlinearities even at low field-strengths as well as a quantum mechanical equilibration current that counteracts the mobility at low frequencies.
Advanced Photonics Research -
First Principle Physics of Computing
Moore’s law is both dead and alive and I here I want to clarify exactly how. Modern computers are based on incredibly simple ideas that we were able to scale up and optimize rapidly over the past 70 years. But we are at a point of transition to entirely new architectures, materials, and physics. This post is dedicated to answer the question of what the limits of computation are in principle, where we are today, what new computers offer as a solution, and what I believe is the future in the short and long-term.
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Image Ranker: The Web App for Fast Ranking of Large Image Collections
Training generative image models requires a way to compare images and provide feedback on which images are better. I built a web app to do just that using the TrueSkill algorithm for accurate and fast Bayesian ranking and various other features.
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BEAMZ: Fast and Easy Electromagnetic Simulation and Inverse Design.
This Python package is built to support multiple backends (e.g. for GPU acceleration), features a high-level API that enables fast prototyping and design with just a few lines of code, includes live visualization of your 3D designs and real-time field propagation, while also providing its own FDTD and FDFD eigen-mode solvers.
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Analog IC Design & Engineering Course
A complete and indepth course to learn VLSI analog and hybrid IC design using Verilog AMS for the hardware description and SPICE for simulating it.