Universal High-Frequency Limits of Periodically Driven Systems: from Dynamical Stabilisation to Floquet Engineering
23.07.2014 at 13:00
Periodically driven systems are currently experiencing an unprecedented flurry of interest. Proposed theoretically, and successfully verified experimentally, nonequilibrium models have been invented in which, by means of an ultra-fast periodic drive, the properties of a system can be changed drastically. For instance, periodic driving is found to turn unstable equilibria into stable ones; neutral atoms can be re-designed to 'feel' magnetic fields much stronger than what coils can produce today; topologically-trivial systems are cast into topological insulators which exhibit robust edge states suitable for quantum computing.
Starting from Floquet theory, I shall discuss the underlying theoretical ideas behind some of these models, giving a classification of different driving scenarios that can be employed to achieve optimal engineering results. I will then present a universal method to obtain the effective high-frequency Hamiltonian, illustrated on several examples. Finally, I shall elaborate on different possibilities of performing measurements in these systems, and introduce the novel concept of Floquet Non-stroboscopic (FNS) evolution, which is not only highly relevant for experiments, but has the potential to reveal the physics of the high-frequency effective Hamiltonian as well.
A318 - Theresienstr. 37