Quantum heat engines (QHEs) have emerged as a promising field at the intersection of quantum mechanics and thermodynamics, offering new perspectives into energy conversion at the nanoscale. In this work, we investigate the performance of a quantum Otto engine using two coupled double quantum dots (DQDs) in an AlGaAs/GaAs heterostructure as the working substance. Applying an external magnetic field \(\vec {B}\) , we explore its effects on the energy spectrum, heat exchange processes, and engine efficiency. Our model considers interdot tunneling, Coulomb interactions, and Zeeman splitting, providing a rich thermodynamic landscape for quantum heat engine operation. We analyze the thermodynamic cycles of the Otto engine, focusing on its ability to function as a heat engine, refrigerator, thermal accelerator, or heater, depending on system parameters. The role of quantum entanglement in optimizing engine performance is also examined. Our results demonstrate that the external magnetic field plays a crucial role in controlling the work performed by the quantum engine, with notable improvements observed under optimal conditions. In addition, we investigate how energy offsets and temperature influence machine operation modes. The findings of this study provide a more comprehensive understanding of how quantum entanglement impacts energy conversion in nanoscale heat engines. This could contribute to the development of highly efficient quantum thermodynamic devices, paving the way for practical implementations in emerging quantum technologies.
