The methods to prepare and control quantum states, and to process their information content, are nowadays a research area as important as the traditional calculation of spectra and physical properties of different quantum systems. The degree of control achievable in condensed systems, ultracold atomic gases and ion crystals is becoming comparable with the one reached decades ago for atomic or molecular few-body systems, leading to ever longer decoherence times. Such high controllabilities and long decoherence times are essential for quantum information processing tasks. Using various numerical and analytical techniques we theoretically model:

- Quantum dots under the effective mass approximation.
- Electronic structures of atoms and molecules.
- Ions and atoms in optical and electromagnetic traps.
- Superconducting qubits.
- Quantum state transfer in chains or graphs.
- Quantum state control.
- Spectral properties of reduced density matrices in bosonic or fermionic systems.
- Asymptotic entanglement properties in open quantum systems.
- Quantum Dynamics of Coupled Spin Systems
- Loschmidt Echoes in Quantum Chaos and Decoherence.