National University of Singapore
CORRELATED PHOTON PAIRS AND MULTIPHOTON STATES FROM A COLD ATOMIC ENSEMBLE
Abstract
dc:description.abstractNarrowband correlated photon pairs are vital for interfacing neutral atom systems and realizing distributed quantum networks. This thesis presents the realization and characterization of a high-brightness, temporally correlated photon-pair source at near-resonant wavelengths of 780 nm and 795 nm in an optically dense cold <sup>87</sup>Rb ensemble. The source is based on a spontaneous four-wave mixing process implemented in a double-Λ energy-level configuration. By systematically varying the pump intensities, detunings, and optical depth, we optimized the photon-pair generation and demonstrated a tunable spectral bandwidth governed by electromagnetically induced transparency. The pair production exhibits quartic scaling with optical depth, revealing the crucial role of collective pair emission beyond independent-emitter models. The generated two-mode squeezed vacuum enables time-resolved measurements of higher-order photon correlations, providing direct evidence of genuine multiphoton states. Building on this foundation, the thesis further explores photon-triplet generation via composite spontaneous six-wave mixing, offering a pathway toward scalable multiphoton quantum light sources compatible with atomic quantum memories.
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
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- LI YIFAN