# Tjark Sievers

Hi, I'm Tjark. I study physics and do stuff with computers.

# Projects

Jan 7, 2024 | Project Showcases

## sunflower

DaisyUI | Hugo | TailwindCSS |A clean Hugo theme with yellows and greens using TailwindCSS and DaisyUI components.

Oct 1, 2023 | Project Showcases

## nolopot

Computational Physics | Python |Python package to calculate bound states and (someday) scattering for non-local potentials. Mostly a testing ground for workflows, packages, tools and coding practices.

May 28, 2023 | Project Showcases

## tjarksievers.de

Docker |This website and its deployment process are available publicly on Gitlab. Deployment is done via Gitlab CI, using Docker containers to separate the different services running on the server. All the pages can be found under pages in respective directories. Each page has its own docker-compose.yml file, these are added in the .gitlab-ci.yml to be deployed. All pages get deployed on every commit to main. Current pages under the domain:

# Blog Posts

Nov 14, 2023 | Blog

## Hopes and Expectations

Erasmus |Currently, I am picking up the first materials to work into the theory of what my thesis will be about. As I am doing that, I am thinking about what I hope to get out of the work on my thesis. It might be a good idea to write down these hopes and expectations, check in again at a later time and see what turns out true. Research with results In my bachelor’s thesis I worked with a software package that is used the research group to produce a lot of interesting results, but I myself did not get to a point where I produced data I could analyse and say what happens there, even with the input data already provided by the group.

Oct 19, 2023 | Blog

## Introduction

in nolopot - A Computational Physics Project

Python |This is the first post in a series of blog posts is about nolopot, a software package that started in a physics lecture I attended in 2022. Currently it can be found on Gitlab. It was a project I did together with another person in the course, and after the course finished I took the code we had so far and build the current infrastructure of testing and deployment around it.

Oct 8, 2023 | Blog

## Finding a Project and Applying for Erasmus Funding

Erasmus |Next year, I will spend 4 months in Sweden for the research phase of my master’s thesis. This post goes over some organisational details, the process of getting support at my home university in Hamburg, getting the funding for it via Eramus and finding a research group and project.

# Lecture Notes

Lecture finished July 2023 | Lecture Notes

## Topology in Condensed Matter Physics

Condensed Matter | Topology |„Topology“ has become a tremendously important discipline for condensed matter physics during the last few decades, especially by the discovery of topological insulators, superconductors, and exotic quasi-particle excitations. This lecture explains the basics of this important but (in physics curricula) rarely taught mathematical discipline and describes selected applications in condensed matter physics.

Lecture finished February 2023 | Lecture Notes

## Quantum Field Theory in Correlated Many-Particle Systems

Condensed Matter |This course covers the application of quantum field theory in condensed matter physics. Quantum field theory as a tool is suited for describing interacting systems, and can as such explain phenomena originating in interaction in condensed matter systems. Topics: Introduction to correlated many-body systems Second Quantization One- and two-particle Green’s functions, Matsubara Formalism Diagrammatic perturbation theory and Feynman diagrams Fermi liquid theory Linear response theory Applications: Magnetism and (Super)conductivity Outlook: Dynamical mean field theory and beyond

Lecture finished January 2023 | Lecture Notes

## Computational Physics with Focus on Time-Dependent quantum mechanics

Computational Physics | Python |The goal of the course is to learn how to solve complex physical problems by means of computer coding and simulations. Topics include various numerical methods that are used in quantum mechanics, as well as in other fields. The problems will be designed with the focus on quantum-mechanical problems, and especially on quantum-dynamical processes. Examples of algorithms and some problems: Lancos algorithm Monte Carlo algorithm Machine Learning Numerov Algorithm Cranck-Nicolson Algorithm Runge-Kutta algorithm Approximate solutions of the time-dependent Schrödinger equation Calculations of the temporal evolution of a wave function, electron density, spin state, spectra, taking into account decoherence, etc.