Posted on

February 2017: Driven open quantum systems and Floquet stroboscopic dynamics

Dimitris Angelakis (left) and Victor Bastidas (right) with collaborators in Germany found a new way to simplify the equations for a driven quantum system, leading to the discovery that driving can protect a quantum state from decoherence

” Pity poor Schrodinger’s cat. As if it weren’t enough to wish a cat into a state of being simultaneously dead and alive, physicists now have an idea for how to keep it that way – and the answer is to shake it. ….”
Read more from the CQT highlight for non specialists “Shaking Schrodinger’s cat may protect it from the environment”


Sebastian Restrepo, Javier Cerrillo, V. M. Bastidas, D. G. Angelakis, T. Brandes, “Driven open quantum systems and Floquet stroboscopic dynamics”, Phys. Rev. Lett. 117, 250401 (2016)


We provide an analytic solution to the problem of system-bath dynamics under the effect of high- frequency driving that has applications in a large class of settings, such as driven-dissipative many-body systems. Our method relies on discrete symmetries of the system-bath Hamiltonian and provides the time evolution operator of the full system, including bath degrees of freedom, without weak-coupling or Markovian assumptions. An interpretation of the solution in terms of the stroboscopic evolution of a family of observables under the influence of an effective static Hamiltonian is proposed, which constitutes a flexible simulation procedure of nontrivial Hamiltonians. We instantiate the result with the study of the spin-boson model with time-dependent tunneling amplitude. We analyze the class of Hamiltonians that may be stroboscopically accessed for this example and illustrate the dynamics of system and bath degrees of freedom.