Quantum Zeno Dynamics Through Stochastic Protocols

Year: 2017

Authors: Muller M.M.; Gherardini S.; Caruso F.

Autors Affiliation: 1) QSTAR, LENS, and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy. 2) QSTAR, LENS, and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy; INFN and Department of Information Engineering, University of Florence, via S. Marta 3, I-50139 Florence, Italy. 3) QSTAR, LENS, and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy.

Abstract: Quantum measurements play a crucial role in quantum mechanics since they perturb, unavoidably and irreversibly, the state of the measured quantum system. More extremely, the constant observation of a quantum system can even freeze its dynamics to a subspace, effectively truncating the Hilbert space of the system. It represents the quantum version of the famous flying arrow Zeno paradox, and is called quantum Zeno dynamics. In general, it can be obtained by applying frequent consecutive quantum measurements that are equally spaced in time. Here, we introduce time disorder in the measurement sequence, and analytically investigate how this temporal stochasticity may affect the confinement probability of the system in the subspace. As main result, we then exploit how different dissipative and coherent Zeno protocols can be generalized to this stochastic scenario. Finally, our analytical predictions are numerically tested on a paradigmatic spin chain where we find a trade-off between a probabilistic scheme with high fidelity (compared to perfect subspace dynamics) and a deterministic one with a slightly lower fidelity, moving further steps towards new schemes of Zeno-based control for future quantum technologies.

Journal/Review: ANNALEN DER PHYSIK (WEINHEIM. INTERNET)

Volume: 529 (9)      Pages from: 1600206  to: 1600206

KeyWords: quantum Zeno effect, quantum Zeno dynamics, weak quantum Zeno regime, stochastic protocols, quantum spin chains
DOI: 10.1002/andp.201600206