FisMat2017 - Submission - View

Abstract's title: Probing Ultrastrong Coupling by Coherent Amplification of Population Transfer
Submitting author: Giuseppe Falci
Affiliation: Dipartimento di Fisica e Astronomia - Università di Catania
Affiliation Address: Via S. Sofia 64 95100 Catania
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Alessandro Ridolfo (Università di Messina), Pietro Di Stefano (Queen's University, Belfast, UK), Elisabetta Paladino (Università di Catania)

Manipulating multilevel coherence in architectures of artificial atoms is a key  issue for achievements in both fundamental and applied physics. Fabrication techniques have recently allowed to produce ultra-strong coupling (USC) between light and matter, a regime where previously unexplored non-perturbative phenomena emerge [1]. While experiments so far provided spectroscopic evidence of USC, we propose the dynamical detection of atom-cavity USC [2,3]. Indeed USC opens a new  channel for photon-pair production, whose detection is a smoking gun its existence in Nature[4]. We show how to coherently amplify this channel to ~100% efficiency by advanced control similar to STIRAP in atomic physics[5]. To this end we propose to operate a three level  atom, where a selected transition is coupled in the USC regime to a  cavity[2]. Unambiguous detection of USC poses strong design constraints on quantum hardware, the requirements being uniquely met  by superconducting artificial atoms (persistent current qubits), driven in the the Vee configuration [3]. Besides its fundamental importance, dynamical detection of USC in state of the art systems would be a benchmark for quantum control in distributed networks, exploiting new ideas of adiabatic protocols in this regime[2,3].

[1] T.Niemczyk,	F.Deppe, et al., Nat. Phys. 6, 772 (2010). Altro exp.	 
[2] G. Falci, P. G. Di Stefano, A. Ridolfo, A. D'Arrigo, G. S. Paraoanu and
E. Paladino, Fort. Phys. online 18 NOV 2016; DOI: 10.1002/prop.201600077, arxiv
[3] G. Falci, A.A. Ridolfo, P.G. Di Stefano and E. Paladino, preprint
[4] R. Stassi, A. Ridolfo, O. Di Stefano, M. J. Hartmann, and S. Savasta,
Phys. Rev. Lett. 110, 243601 (2013)
[5] N.V. Vitanov, A.A. Rangelov, B.W. Shore, and K. Bergmann,
Rev. Mod. Phys. 89, 015006 (2017).