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Résumé |
Typical schemes for generating correlated states of light require a highly
nonlinear medium that is strongly coupled to an optical mode. However,
unavoidable dissipative processes, which cause photon loss and blur nonlinear
quantum effects, often impede such methods. In this seminar, I will report on
a recent experimental demonstration of the opposite approach [1]. Using a
strongly dissipative, weakly coupled medium, we generate and study strongly
correlated states of light. Specifically, we study the transmission of
resonant light through an ensemble of non-interacting atoms that weakly couple
to a guided optical mode. Dissipation removes uncorrelated photons while
preferentially transmitting highly correlated photons created through
collectively enhanced nonlinear interactions. As a result, the transmitted
light constitutes a strongly correlated many-body state of light, revealed in
the second-order correlation function. The latter exhibits strong antibunching
or bunching, depending on the optical depth of the atomic ensemble. The
demonstrated mechanism opens a new avenue for generating nonclassical states
of light and for exploring correlations of photons in non-equilibrium systems
using a mix of nonlinear and dissipative processes. Furthermore, our scheme
may turn out transformational in quantum information science. For example, it
offers a fundamentally new approach to realizing single photon sources, which
may outperform sources based on single quantum emitters with comparable
coupling strength.
References
[1] S. Mahmoodian, M. Čepulkovskis, S. Das, P. Lodahl, K. Hammerer, and A. S.
Sørensen, Phys. Rev. Lett. 121, 143601 (2018). |
