Quantum Fluctuations in Mesoscopic Systems

Abstract

Recent experimental results point to the existence of coherent quantum phenomena in systems made of a large number of particles, despite the fact that for many-body systems the presence of decoherence is hardly negligible and emerging classicality is expected. This behaviour hinges on collective observables, named quantum fluctuations, that retain a quantum character even in the thermodynamic limit: they provide useful tools for studying properties of many-body systems at the mesoscopic level, in between the quantum microscopic scale and the classical macroscopic one. We hereby present the general theory of quantum fluctuations in mesoscopic systems and study their dynamics in a quantum open system setting, taking into account the unavoidable effects of dissipation and noise induced by the external environment. As in the case of microscopic systems, decoherence is not always the only dominating effect at the mesoscopic scale: certain type of environments can provide means for entangling collective fluctuations through a purely noisy mechanism.

51 pages, LaTeX

References in corpus (14)

• Many-Body Physics with Ultracold Gases
• Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
• Theory of ultracold Fermi gases
• Atom Interferometers
• Quantum States and Phases in Driven Open Quantum Systems with Cold Atoms
• Sudden Death of Entanglement
• Quantum Non-Markovianity: Characterization, Quantification and Detection
• Quantum technologies with hybrid systems
• Testing the limits of quantum mechanical superpositions
• Cold Bosons in Optical Lattices
• Entangling oscillators through environment noise
• Quantum teleportation from light beams to vibrational states of a macroscopic diamond
• Classification of macroscopic quantum effects
• Long-lived mesoscopic entanglement between two damped infinite harmonic chains