Complexity of controlling quantum many-body dynamics

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Date: 
2014-04-23
Author(s): 

T. Caneva, A. Silva, R. Fazio, S. Lloyd, T. Calarco, and S. Montangero

Reference: 

Phys. Rev. A 89, 042322 (2014)
http://dx.doi.org/10.1103/PhysRevA.89.042322

We demonstrate that arbitrary time evolutions of many-body quantum systems can be reversed even in cases when only part of the Hamiltonian can be controlled. The reversed dynamics obtained via optimal control—contrary to standard time-reversal procedures—is extremely robust to external sources of noise. We provide a lower bound on the control complexity of a many-body quantum dynamics in terms of the dimension of the manifold supporting it, elucidating the role played by integrability in this context.