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We theoretically investigate a thermoelectric heat engine based on a single-level quantum dot, calculating average quantities such as current, heat current, output power, and efficiency, as well as fluctuations (noise). Our theory is based on a diagrammatic expansion of the memory kernel together with counting statistics, and we investigate the effects of strong interactions and next-to-leading or
Quantum cascade lasers (QCLs) are periodic semiconductor heterostructures, capable of producing laser gain. They have become an important source of coherent radiation in the mid infrared, and THz frequency regions. QCLs are non-linear electric devices, and often have bias regions of negative differential resistivity (NDR). These regions are inherently unstable, and electric field domains (EFDs) fo
Quantum dots are model systems for quantum thermoelectric behavior because of their ability to control and measure the effects of electron-energy filtering and quantum confinement on thermoelectric properties. Interestingly, nonlinear thermoelectric properties of such small systems can modify the efficiency of thermoelectric power conversion. Using quantum dots embedded in semiconductor nanowires,
Transport through nanosystems is treated within the second-order von Neumann approach. This approach bridges the gap between rate equations which neglect level broadening and cotunneling, and the transmission formalism, which is essentially based on the single-particle picture thereby treating many-particle interactions oil an approximate level. Here we provide an alternative presentation of the m
The gain profile of a quantum cascade laser is strongly influenced by the lifetime of the carriers in the upper and lower laser state. The quantitative description of gain within the concept of nonequilibrium Green's functions allows for a detailed understanding of various features affecting the gain spectrum: Compensation effects between scattering processes in the upper and lower laser level, re
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In small systems with large fluctuations, the classical description of thermodynamics is no longer sufficient which has led to the development of stochastic thermodynamics. One important result from stochastic thermodynamics is that with measurement and feedback it is possible to use those fluctuations to extract work from a single heat bath coupled to the system. This is thanks to the connection
In this thesis we employ the non-equilibrium Green’s function (NEGF) method to study both finite and infinite systems. We develop a codebase capable of computing the steady state interacting NEGF in open systems, i.e. tight-binding leads contacting a central region, in both Hartree-Fock (HF) and second Born (2B) approximations of particle-particle interactions. Furthermore, we use the exact intera
https://www.biologyeducation.lu.se/education/career - 2026-07-13
Radiation Safety and Society: Building Sweden’s Interdisciplinary Capacity for Nuclear Futures Energy production based on fission is complex, and safety aspects for workers, for the general public and for the environment are crucial, both to fulfil regulatory requirements and for the societal acceptance of the technology. We bring together researchers from four faculties at Lund University (Scienc
https://www.particle-nuclear.lu.se/sense-sciences-enhance-safety-nuclear-energy - 2026-07-13
With nanotechnology, our researchers can create very small structures. The technology enables the development of materials that hold promise for future advances in fields such as information technology, sustainability and precision medicine. When a material becomes very small, it can acquire entirely new properties. On the nanoscale, a substance can behave in a radically different way than when it
https://www.lunduniversity.lu.se/research-and-innovation/focus-areas/strategic-research-areas/nanoscience - 2026-07-13
Master's programmesThe Division is responsible for two master's programmes in Material Science and X-ray and Neutron Science. These programmes are made in connection with the two major multidisciplinary research facilies in Lund: MAX-IV laboratory and European Spallation Source.Master's programme in Materials Science (Lund University's website)Master's programme in X-ray and Neutron Science (Lund
https://www.sljus.lu.se/education - 2026-07-13
