Regensburg 2019 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 39: Quantum matter: Chaos, correlation
DY 39.5: Vortrag
Mittwoch, 3. April 2019, 18:15–18:30, H6
Bloch-like oscillations in periodically driven Dirac systems — •Vanessa Junk1, Phillipp Reck2, Cosimo Gorini1, and Klaus Richter1 — 1Institut für Theoretische Physik, Universität Regensburg, Germany — 2CEA, Paris-Saclay, France
Since the discovery of Floquet topological insulators [1] the scientific interest in periodically driven systems has been growing rapidly. However, there are still a lot of open questions concerning the dynamics of particles in the Floquet quasi-band structure and analogies to undriven Bloch bands.
We show that Bloch-like oscillations can be observed in a continuous Dirac system when periodically opening a mass gap. By applying an additional static electric field, a particle is driven through the resulting Floquet quasi-band structure. As this band structure is oscillatory in k-space, the position- and velocity expectation value of the particle are oscillating as well and resemble those of conventional Bloch oscillations [2]. Additionally, the characteristic features of the Floquet quasi-bands are displayed in the movement of the particle. Hence, these Floquet-Bloch oscillations could also provide a way to directly measure the quasi-band structure. On top of that, we find features of Zitterbewegung in the particle velocity caused by the Dirac character of our system.
[1] N. H. Lindner, G. Refael, and V. Galitski, Nature Physics 7, 13368 (2016)
[2] K. Leo, P. Haring Bolivar, F. Brüggemann, R. Schwedler, and K. Köhler, Solid State Comm. 84, 943 (1992)