@article {Sharma2014,
	title = {Loschmidt echo and dynamical fidelity in periodically driven quantum systems},
	journal = {Europhysics letters (Print)},
	volume = {106},
	year = {2014},
	publisher = {EDP sciences},
	address = {Les Ulis},
	abstract = {We study the dynamical fidelity F(t) and the Loschmidt echo L(t), following a periodic driving of the transverse magnetic field of a quantum Ising chain (back and forth across the quantum critical point) by calculating the overlap between the initial ground state and the state reached after n periods tau. We show that [log F(n tau)]/L (the logarithm of the fidelity per site) reaches a steady value in the asymptotic limit n -> infinity, and we derive an exact analytical expression for this quantity. Remarkably, the steady-state value of [log F(n tau -> infinity)]/L shows memory of non-trivial phase information which is instead hidden in the case of thermodynamic quantities; this conclusion, moreover, is not restricted to 1-dimensional models. Copyright (C) EPLA, 2014},
	issn = {0295-5075},
	doi = {10.1209/0295-5075/106/67003},
	author = {Sharma, Shraddha and Russomanno, Angelo and Santoro, Giuseppe E. and Dutta, Amit}
}
