arXiv subjects

Albert Verdeny

Publications and source records attributed to Albert Verdeny.

5 recordsLinked to original sources

arXiv2016

Quasi-periodically driven quantum systems

Floquet theory provides rigorous foundations for the theory of periodically driven quantum systems. In the case of non-periodic driving, however, the situation is not so well understood. Here, we provide a critical review of the theoretical framework developed for quasi-periodically driven quantum systems. Although the theoretical footing is still under development, we argue that quasi-periodically driven quantum systems can be treated with generalizations of Floquet theory in suitable parameter regimes. Moreover, we provide a generalization of the Floquet-Magnus expansion and argue that quasi-periodic driving offers a promising route for quantum simulations.

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arXiv2015

Structure-dynamics relation in shaken optical lattices

Shaken optical lattices permit to coherently modify the tunneling of particles in a controllable manner. We introduce a general relation between the geometry of shaken lattices and their admissible effective dynamics. Using three different examples, we illustrate the symmetries of the emerging tunneling rates. The results provide a clear framework to understand the relation between lattice geometry and accessible dynamics, and a tool to straightforwardly derive truncated effective Hamiltonians on arbitrary geometries.

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arXiv2015

Tunable Chern insulator with shaken optical lattices

Driven optical lattices permit the engineering of effective dynamics with well-controllable tunneling properties. We describe the realization of a tunable a Chern insulator by driving particles on a shaken hexagonal lattice with optimally designed polychromatic driving forces. Its implementation does not require shallow lattices, which favors the study of strongly-correlated phases with non-trivial topology.

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arXiv2014

Optimal Control of Effective Hamiltonians

We present a systematic scheme for optimization of quantum simulations. Specifically, we show how polychromatic driving can be used to significantly improve the driving of Raman transitions in the Lambda system, which opens new possibilities for controlled driven-induced effective dynamics.

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arXiv2013

Accurate effective Hamiltonians via unitary flow in Floquet space

We present a systematic construction of effective Hamiltonians of periodically driven quantum systems. Because of an equivalence between the time dependence of a Hamiltonian and an interaction in its Floquet operator, flow equations, that permit to decouple interacting quantum systems, allow us to identify time-independent Hamiltonians for driven systems. With this approach, we explain the experimentally observed deviation of expected suppression of tunneling in ultracold atoms.

quant-ph↗