activity
20202026
collaborators

9 papers

quant-ph2026

Quantum orientation, Noether structure, composition of systems and operations

Heinz-Jürgen Schmidt

In this paper we argue that, in addition to the statistical structure of quantum theory, another structure, referred to here as the ``Noether structure," is necessary to describe t…

physics.class-ph2025

On the motion of a point charge in a plate capacitor considering influence effects

Heinz-Jürgen Schmidt, Thomas Bröcker

A point charge between the plates of a capacitor generates an influence charge distribution on the plates that modify the electric field acting upon the point charge. This effect i…

cond-mat.stat-mech2025

Ground states of classical spin polygons: Rigorous results and examples

Wojciech Florek, Heinz-Jürgen Schmidt, Katarzyna Jaśniewicz-Pacer

We present a comprehensive and rigorous analysis of the lowest energy configurations (LECs) of classical spin polygons characterized by arbitrary couplings between neighboring spin…

physics.class-ph2025

Coarse-grained entropy balance of the Szilard engine

Heinz-Jürgen Schmidt, Thomas Bröcker

In order to reconcile the entropy reduction of a system through external interventions that are linked to a measurement with the second law of thermodynamics, there are two main pr…

quant-ph2024

Galilean decoherence and quantum measurement

Heinz-Jürgen Schmidt

In this study, we present a modified quantum theory, denoted as , which introduces mass-dependent decoherence effects. These effects are derived by averaging the influence…

math-ph2024

A generalization of the Choi isomorphism with application to open quantum systems

Heinz-Jürgen Schmidt

Completely positive transformations play an important role in the description of state changes in quantum mechanics, including the time evolution of open quantum systems. One usefu…