AUTHOR=Gómez-Ruiz Fernando J. , Acevedo Oscar L. , Rodríguez Ferney J. , Quiroga Luis , Johnson Neil F. 

TITLE=Pulsed Generation of Quantum Coherences and Non-classicality in Light-Matter Systems

JOURNAL=Frontiers in Physics

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2018.00092

DOI=10.3389/fphy.2018.00092

ISSN=2296-424X

ABSTRACT=<p>We show that a pulsed stimulus can be used to generate many-body quantum coherences in light-matter systems of general size. Specifically, we calculate the exact time-evolution of an <italic>N</italic> qubit system coupled to a global boson field, in response to an up-down pulse. The pulse is chosen so that the system dynamically crosses the system's quantum phase transition on both the up and down portion of the cycle. We identify a novel form of dynamically-driven quantum coherence emerging for general <italic>N</italic> and without having to access the empirically challenging strong-coupling regime. Its properties depend on the <italic>speed</italic> of the changes in the stimulus. Non-classicalities arise within each subsystem that have eluded previous analyses. Our findings show robustness to losses and noise, and have potential functional implications at the systems level for a variety of nanosystems, including collections of <italic>N</italic> atoms, molecules, spins, or superconducting qubits in cavities—and possibly even vibration-enhanced light-harvesting processes in macromolecules.</p>