Conveners
Applications outside particle physics: TR6
- Carsten Urbach (University of Bonn)
Applications outside particle physics: TR6
- Lena Funcke (University of Bonn)
Organic semiconductors such as rubrene or pentacene feature an unconventional charge transport mechanism that is entirely driven by dynamical disorder created by thermal bath of soft phonons, and that is very nontrivial to simulate from first principles. We report on Hybrid Monte-Carlo simulations of charge transport in organic semiconductors, and discuss physical similarities with...
Despite its many advantages, the sensible application of the Hybrid Monte Carlo (HMC) method is often hindered by the presence of large - or even infinite - potential barriers. These potential barriers partition the configuration space into distinct sectors, which leads to ergodicity violations and biased measurements of observables.
In this work, we address this problem by augmenting the HMC...
Chern-Simons theory is a topological quantum field theory with numerous applications in condensed matter and high-energy physics, including the study of anomalies, fermion/boson dualities, and the fractional quantum Hall effect. The lattice formulation of pure Chern-Simons theory faces a doubling problem, which can be resolved by incorporating a Maxwell term, resulting in Maxwell-Chern-Simons...
Two-dimensional adjoint QCD is the theory of a single Majorana fermion coupled to an SU(N) gauge field in the adjoint representation in (1+1) spacetime dimensions. The theory has been studied as a toy model of confinement in gauge theories: it confines test charges when the adjoint fermion is massive but deconfines when the adjoint fermion is massless. We present a preliminary calculation of...
Real time evolution of a scalar field theory is investigated. The severe sign problem is circumvented using the Complex Langevin equation. The naive application of the method breaks down for extended real times due to the appearance of boundary terms. We use the kernel freedom of the complex Langevin equation to push the breakdown to larger real-times. We search for the optimal kernel using...
The sign problem that arises in Hybrid Monte Carlo calculations can be mitigated by deforming the integration manifold. While simple transformations are highly efficient, they reach a limit with decreasing temperature and increasing interaction. Machine learning models have demonstrated the ability to push further, but require additional computational effort and upfront training.
We examine...
Generative models, in particular normalizing flows, have demonstrated exceptional performance in learning probability distributions across various domains of physics, including statistical mechanics, collider physics, and lattice field theory. In lattice field theory, using normalizing flows for accurately learning the Boltzmann distribution has been applied to a wide range of tasks, such as...
The temporal finite volume induces significant effects in Monte Carlo simulations of systems in low dimensions. An example is graphene, a 2-D hexagonal system known for its unique electronic properties and numerous potential applications.
In this work, we explore the behavior of fermions on a graphene sheet with a Hubbard-type interaction characterized by coupling $U$. This system exhibits...
We present one- and two-body measurements for the Hubbard model on the honeycomb (graphene) lattice from ab-initio HMC. Excitons, or particle/hole excitations in low-dimensional systems are analogous to the pion in QCD, but without confinement whether they are bound is a dynamical question. By measuring one- and two-body correlators across various spin- isospin channels we can compute energy...
