Ph

Colloquium: Quantum optics using atomic arrays

Datum
03.12.2018 
Zeit
16:30 Uhr - 17:30 Uhr 
Sprecher
Professor Darrick Chang 
Institut
ICFO - The Institute of Photonic Sciences, Castelldefels, Spain 
Teil der Serie
MPI-PKS Kolloquium 
Sprache
en 
Hauptthema
Physik: Theoretische Physik
Zusammenfassung

Ensembles of atoms or other quantum emitters are envisioned to be an important component of quantum applications, ranging from quantum memories for light to photon-photon gates to metrology. It has historically been an outstanding challenge to exactly solve for the quantum dynamics of an optical field as it propagates through and interacts with an ensemble. The standard axiomatic approach is to use the one-dimensional Maxwell-Bloch equations, which treats the interaction between the ensemble and a quasi-1D optical mode of interest, while the interaction with the remaining 3D continuum of modes is assumed to result in independent spontaneous emission of excited atoms. Strictly speaking, this assumption cannot be correct, as the emission of light is a wave phenomenon, and thus the emitted intensity must depend on interference and correlations between the atoms.

Here, we discuss an alternative theoretical approach, which accounts for interference and the precise atomic positions. In this formalism, an interacting quantum spin model describes the dynamics of the atomic internal degrees of freedom under multiple photon scattering, while the field properties can subsequently be re-constructed from the spin correlations. Using this model, we then show how interference can be exploited as an extremely powerful resource to suppress the unwanted emission of light and the subsequent loss of information into undesirable directions. The effects of interference are particularly prominent in ordered arrays of emitters. As two specific examples, we construct a new protocol for a quantum memory for light based upon an ordered array, whose error rate as a function of system resources scales exponentially better than previously known bounds. We also show the interrogation time in an optical lattice clock can be significantly extended, through the excitation of collective subradiant atomic states whose spontaneous emission rates are strongly suppressed. These results raise the intriguing question of whether interference can be used to broadly re-define the performance limits of all applications involving atomic light-matter interfaces.

 

Letzte Aktualisierung: 03.12.2018 00:07.

Vortragsort 

Max-Planck-Institut für Physik komplexer Systeme (Seminarroom 1+2) 
Nöthnitzer Straße 38
01187 Dresden
Telefon
+ 49 (0)351 871 0 
E-Mail
Max-Planck-Institut für Physik komplexer Systeme 
Homepage
http://www.mpipks-dresden.mpg.de 

Veranstalter 

Max-Planck-Institut für Physik komplexer Systeme (MPI-PKS)
Nöthnitzer Straße 38
01187 Dresden
Telefon
+ 49 (0)351 871 0 
E-Mail
Max-Planck-Institut für Physik komplexer Systeme (MPI-PKS) 
Homepage
http://www.mpipks-dresden.mpg.de 
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