On Monday, 20.08.2018, we will have  Haggai Landa from the Institute de Physique Theorique de Université Paris-Sud, France as a guest.

He will present a SFB-seminar at PTB, RZB 11, at 10:00 h on Monday, 20.08.2018.

Title and Abstract:

Far-from-equilibrium heating and laser cooling dynamics in radio-frequency Paul traps

Strong driving by periodic or stochastic forces can be a powerful tool allowing to shape and even completely alter the properties of a physical system. Due to its essential dynamical nature, the modelling of the ensuing state can be challenging. In closed, Floquet driven systems which are periodically modulated in time, the resulting phases, although time-dependent, are often described as arising from a time-independent effective Hamiltonian. In open systems driven with nonequilibrium microscopic dynamics, a description in terms of an emergent equilibrium is another key idea. Understanding the extent of validity of such effective descriptions and possible directions going beyond it, is important in practice and fundamentally interesting.
I will discuss a few recent theory studies and an experiment with ultracold ions trapped in vacuum within a Paul trap, which yield surprising insights into these questions. In particular, I will describe a theory study of the Hamiltonian Floquet dynamics of an ion in a surface-electrode trap [1], its heating and laser cooling dynamics far from equilibrium [2], and an observed emergent equilibrium in an ion crystal featuring transport of ratchet-like discrete solitons [3].

[1] V. Roberdel, D. Leibfried, D. Ullmo, and H. Landa, Phys. Rev. A 97, 053419 (2018).

[2] A. Maitra, D. Leibfried, D. Ullmo, and H. Landa, in preparation.

[3] J. Brox, P. Kiefer, M. Bujak, H. Landa, T. Schaetz, Phys. Rev. Lett. 119, 153602 (2017).

Guests are welcome!