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A: Fachverband Atomphysik

A 12: Ultracold plasmas and Rydberg atoms (with Q)

A 12.2: Talk

Monday, March 18, 2013, 17:00–17:15, E 415

Spontaneous avalanche ionization of a strongly blockaded Rydberg gas — •Christoph S. Hofmann, Martin Robert-de Saint-Vincent, Hanna Schempp, Georg Günter, Shannon Whitlock, and Matthias Weidemüller — Physikalisches Institut, Universität Heidelberg, Philosophenweg 12, 69120 Heidelberg

We report the sudden and spontaneous evolution of an initially correlated gas of repulsively interacting Rydberg atoms to an ultracold plasma [1]. Under continuous laser coupling we create a Rydberg ensemble in the strong blockade regime, which at longer times undergoes an ionization avalanche. By combining optical imaging and ion detection, we access the full information on the dynamical evolution of the system, including the rapid increase in the number of ions and a sudden depletion of the Rydberg and ground state densities. Rydberg–Rydberg interactions are observed to strongly affect the dynamics of plasma formation. We use a coupled rate-equation model to describe our data and to reveal that the initial correlations of the Rydberg ensemble should persist through the avalanche. The latter would mitigate disorder-induced-heating [2], and offer a route to enter new strongly-coupled regimes.
M. Robert-de Saint-Vincent et al. arXiv:1209.4728 (2012)
M. Murillo PRL 87 115003 (2001)