FisMat2017 - Submission - View

Abstract's title: Quantum phase gate based on quantum Zeno dynamics
Submitting author: Cosimo Lovecchio
Affiliation: LENS, Dipartimento di Fisica ed Astronomia - Università di Firenze
Affiliation Address: Via Nello Carrara 1, Sesto Fiorentino, 50019
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: H. V. Do (LENS, Dipartimento di Fisica e Astronomia - Università degli Studi di Firenze, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy) , S. Gherardini (LENS, Dipartimento di Fisica e Astronomia - Università degli Studi di Firenze, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy), M. Muller (LENS, Dipartimento di Fisica e Astronomia - Università degli Studi di Firenze, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy), F. Caruso (LENS, Dipartimento di Fisica e Astronomia - Università degli Studi di Firenze, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy, Istituto Nazionale di Ottica INO-CNR, Largo Enrico Fermi 4, 50125 Firenze), and F. S. Cataliotti (LENS, Dipartimento di Fisica e Astronomia - Università degli Studi di Firenze, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy, Istituto Nazionale di Ottica INO-CNR, Largo Enrico Fermi 4, 50125 Firenze)
Abstract

Quantum Zeno dynamics (QZD) were recently demonstrated with Bose-Einstein condensates (BEC) [1] and with Rydberg atoms [2]. In our experiment we work with internal degrees of freedom of a BEC of 87 Rb atoms created on an Atom Chip. In the presence of a constant magnetic bias field, we drive the dynamics between magnetics sub levels on the same hyperfine ground states using a radio-frequency (RF) field. We exploited QZD with a Raman coupling between different hyperfine levels to constrain atoms to evolve in two Hilbert subspaces. We choose the 4 logical input states of a 2-qbit gate among the two subspaces; with D-CRAB optimization [3] we design a control RF pulse to perform a phase gating operation. We make use of a recently developed state reconstruction technique [4] to perform input and output state tomography in order to characterize the gate operation. Given that in the same system we can make use of Raman and microwave transitions between the different hyperfine manifolds in order to perform single q-bit operations, our use of QZD allows the demonstration of a complete set of logical gates within a single rubidium atom.


REFERENCES
[1] F. Schafer et al., Nature Commun., 5, 3194 (2014).
[2] A. Signoles et al., Nature Physics 10, 715–719 (2014)
[3] N. Rach et al., Phys. Rev. A 92, 062343 (2015)
[4] C. Lovecchio et al., New J. Phys. 17, 093024 (2015)