Quench dynamics of two coupled zig-zag ion chains

• Novel dynamical phenomenology of two coupled zig-zag ion chains following a trap quench is explored.
• Transient ordered ion configurations are unraveled in non-equilibrium dynamics dominated by irregular behavior.
• A measure for the diagnosis of this transient order is introduced and applied.
• Energy transfer between a few eigen modes is identified as the key mechanism for the occurrence of the ordered configurations.

We explore the non-equilibrium dynamics of two coupled zig-zag chains of trapped ions in a double well potential. Following a quench of the potential barrier between both wells, the induced coupling between both chains due to the long-range interaction of the ions leads to the complete loss of order in the radial direction. The resulting dynamics is however not exclusively irregular but leads to phases of motion during which various ordered structures appear with ions arranged in arcs, lines and crosses. We quantify the emerging order by introducing a suitable measure and complement our analysis of the ion dynamics using a normal mode analysis showing a decisive population transfer between only a few distinguished modes.