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Master Thesis: Many-Body Physics of Strongly Interacting Rydberg Atoms

2 mins
Quantum Physics Rydberg Atoms Monte Carlo Cold Atoms
Table of Contents

Overview

Many-Body Physics of Strongly Interacting Rydberg Atoms Universita degli Studi di Pisa, Dipartimento di Fisica, 2015. Advisor: Prof. Oliver Morsch.

This thesis explores the out-of-equilibrium dynamics of strongly interacting Rydberg atom ensembles, where long-range van der Waals interactions lead to collective phenomena such as the Rydberg blockade and facilitated excitation.

Key Topics

  • Rydberg blockade: When one atom is excited to a Rydberg state, the strong C_6/r^6 van der Waals interaction shifts neighboring atoms out of resonance, preventing their excitation within a blockade radius.
  • Facilitation dynamics: With a finite detuning, excitation is suppressed for isolated atoms but enhanced at a specific facilitation shell where the vdW shift compensates the detuning, creating spatially correlated excitation avalanches.
  • Rate equations and KMC: The excitation dynamics are modeled via rate equations with Lorentzian line profiles, solved using kinetic Monte Carlo (Gillespie algorithm) methods.
  • Mechanical dynamics: Excited atoms experience vdW repulsion and move in space, coupling the internal (excitation) and external (motional) degrees of freedom.

The Simulation

The Rydberg atom simulation on the Projects page is directly inspired by this thesis and the johannes C++ library developed for it. It implements the same physics: rate-equation excitation with facilitation, van der Waals forces, and velocity Verlet integration for Rb-87 atoms in the 70s Rydberg state.