Gessner M. Dynamics and Characterization of Composite Quantum Systems

Springer International Publishing AG, 2017. — 357 p. — (Springer Theses) — ISBN: 9783319444581Due to experimental developments over the past decades on quantum optical and atomic systems, a wealth of composite quantum systems of variable sizes has become accessible under rather well-controlled conditions. Typical systems of tens of trapped ions or thousands of cold neutral atoms are usually too large to fully measure all of their constituents’ microscopic quantum properties, but not large enough to be described completely in terms of thermodynamic quantities. This challenging intermediate regime of controllable quantum few- to many-body systems is particularly interesting, since it combines a variety of different phenomena and applications, ranging from quantum information theory to solid-state physics.
The effective characterization of these systems requires flexible and experimentally feasible observables, complemented by efficient theoretical methods and models. In this dissertation we employ concepts from the fields of open quantum systems, quantum information theory, quantum many-body theory and physical chemistry, to construct dynamical approaches for the study of various aspects of correlations, and to describe spectral and dynamical features of complex, interacting quantum systems. Some of the developed theoretical ideas are complemented by experimental realizations with trapped ions or photons.Local Detection of Correlations in Composite Quantum Systems
From Local Operations to Collective Dephasing: Behavior of Correlated Quantum States
Quantum Phase Transition in a Family of Quantum Magnets
Multidimensional Nonlinear Spectroscopy of Controllable Quantum Systems Systems
Open Quantum Systems of Identical Particles
Summary and Conclusions
Appendixes
Derivation of the Bosonic Master Eq. (6.151)
Representation of Double-Commutator Terms in a Larger Basis
Transformation Properties of Interaction-Picture Operators