Ellipticity dependence transition induced by dynamical Bloch oscillations

Bloch-Zener oscillations across a merging transition of Dirac points.

Bloch oscillations are a powerful tool to investigate spectra with Dirac points. By varying band parameters, Dirac points can be manipulated and merged at a topological transition toward a gapped phase. Under a constant force, a Fermi sea initially in the lower band performs Bloch oscillations and may Zener tunnel to the upper band mostly at the location of the Dirac points. The tunneling proba...

Long lived matter waves Bloch oscillations and dynamical localization by time dependent nonlinearity management

We introduce a new method to achieve long lived Bloch oscillations and dynamical localization of matter wave gap solitons in optical lattices. The method is based on time dependent modulations of the nonlinearity which can be experimentally implemented by means of the Feshbach resonance technique. In particular, we show that the width of the wave packet is preserved if time modulations of the n...

Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch oscillations

Dynamics of Bloch oscillations

We study the dynamics of Bloch oscillations in a one-dimensional periodic potential plus a (relatively weak) static force. The tight-binding and single-band approximations are analysed in detail, and also in a classicalized version. A number of numerically exact results obtained from wavepacket propagation are analysed and interpreted in terms of the tight-binding and single-band model, both in...

Control of interaction-induced dephasing of Bloch oscillations.

We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice. We quantify the dephasing in terms of the width of the quasimomentum distribution and measure its dependence on time for different interaction strengths which we control by means of a Feshbach resonance. For minimal interaction, the dephasing time is incr...