Quantum Zeno Dynamics Through Stochastic Protocols. Issue 9 (21st July 2017)

• Record Type: Journal Article
• Authors: Müller, Matthias M.; Gherardini, Stefano; Caruso, Filippo
• Is Part Of: Annalen der Physik. Volume 529:Issue 9(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-07-21
• Subjects: Quantum Zeno dynamics -- Spin chains -- Open quantum systems -- Decoherence free subspaces; Physics -- Periodicals; Chemistry -- Periodicals; 530.05
• DOI: 10.1002/andp.201600206
• Languages: English
• ISSNs: 0003-3804

Abstract

Abstract : The authors discuss effects of localization in a many‐body system subjected to random interaction. For a spin chain we investigate different protocols of coherent and dissipative control to confine the dynamics of the system, effectively implementing a stochastic version of so‐called Quantum Zeno dynamics. 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.