Quantum dynamical phase transition in a system with many-body interactions

ERNESTO PABLO DANIELI; GONZALO AGUSTÍN ÁLVAREZ; PATRICIA REBECA LEVSTEIN; HORACIO MIGUEL PASTAWSKI

SOLID STATE COMMUNICATIONS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2007 vol. 141 p. 422 - 426

0038-1098

We introduce a microscopic Hamiltonian model of a two level system with many-body interactions with an environment whose excitation dynamics is fully solved within the Keldysh formalism. If a particle starts in one of the states of the isolated system, the return probability oscillates with the Rabi frequency w0. For weak interactions with the environment 1/tSE < 2w0, we find a slower oscillation whose amplitude decays with a rate 1/tf = 1/(2tSE). However, beyond a finite critical interaction with the environment, 1/tSE > 2w0, the decay rate becomes 1/tf µ w02 tSE. The oscillation period diverges showing a quantum dynamical phase transition to a Quantum Zeno phase.