A5102926582- Thermal properties of materials
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Molecular Junctions and Nanostructures
- Matrix Theory and Algorithms
- Scientific Research and Discoveries
- Machine Learning in Materials Science
- Advanced Thermodynamics and Statistical Mechanics
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Advanced Chemical Physics Studies
- Perovskite Materials and Applications
University of Oxford
2023-2024
The properties of excitons, or correlated electron-hole pairs, are paramount importance to optoelectronic applications materials. A central component exciton physics is the interaction, which commonly treated as screened solely by electrons within a material. However, nuclear motion can screen this Coulomb interaction well, with several recent studies developing model approaches for approximating phonon screening excitonic properties. While these tend improve agreement experiment, they rely...
We present a scalable single-particle framework to treat electronic correlation in molecules and materials motivated by Green's function theory. derive size-extensive Brillouin-Wigner perturbation theory from the introducing Goldstone self-energy. This new ground state energy, referred as Quasi-Particle MP2 (QPMP2), avoids characteristic divergences both second-order Møller-Plesset Coupled Cluster Singles Doubles within strongly correlated regime. show that exact energy properties of Hubbard...
Superconductivity in doped SrTiO$_3$ was discovered 1964, the first superconducting transition observed a semiconductor. However, mechanism behind electron pairing remains subject of debate. By developing theoretical framework to incorporate dynamical lattice screening electronic Coulomb interactions semiconductors and insulators, we demonstrate analytically that long-range electron-phonon described by generalized multi-phonon Fr\"ohlich result phonon-mediated electron-electron attraction...
Ab initio downfolding describes the electronic structure of materials within a low-energy subspace, often around Fermi level. Typically starting from mean-field calculations, this framework allows for calculation one- and two-electron interactions, parametrization many-body Hamiltonian representing active space interest. The subsequent solution such Hamiltonians can provide insights into physics strongly-correlated materials. While phonons substantially screen electron-electron...
Understanding the processes governing dissociation of excitons to free charge carriers in semiconductors and insulators is central importance for photovoltaic applications. Dyson's <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>S</a:mi></a:math>-matrix formalism provides a framework computing scattering rates between quasiparticle states derived from same underlying Hamiltonian, often reducing familiar Fermi's “golden rule” like expressions at first order. By presenting rigorous...
We present a scalable single-particle framework to treat electronic correlation in molecules and materials motivated by Green's function theory. derive size-extensive Brillouin-Wigner perturbation theory from the introducing Goldstone self-energy. This new ground state energy, referred as Quasi-Particle MP2 (QPMP2), avoids characteristic divergences both second-order M{\o}ller-Plesset Coupled Cluster Singles Doubles within strongly correlated regime. show that exact energy properties of...