Towards quantum telecommunication and a Thorium nuclear clock

Frequency conversion;Four-wave mixing;Rubidium;Cold atoms;Quantum telecommunication;Wavelength conversion;Optically thick gas;DLCZ;Multiplexing;Thorium;Thorium-229;Thorium-232;Triply charged thorium;Nuclear clock;Isomer transition

Radnaev, Alexander G. ; Kuzmich, Alex Physics Brown, Kenneth First, Phillip Jefferts, Steven Kennedy, T. A. Brian ; Kuzmich, Alex

University:Georgia Institute of Technology

Department:Physics

关键词: Frequency conversion;    Four-wave mixing;    Rubidium;    Cold atoms;    Quantum telecommunication;    Wavelength conversion;    Optically thick gas;    DLCZ;    Multiplexing;    Thorium;    Thorium-229;    Thorium-232;    Triply charged thorium;    Nuclear clock;    Isomer transition;   

Others  :  https://smartech.gatech.edu/bitstream/1853/50120/1/radnaev_alexander_g_201212_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

This thesis presents the investigations of Rubidium atoms in magneto-optical traps and triply charged Thorium ions in electrodynamic traps for future advances in long-distance quantum telecommunication, next generation clocks, and fundamental tests of current physical theories. Experimental realizations of two core building blocks of a quantum repeater are described: a multiplexed quantum memory and a telecom interface for long-lived quantum memories. A color change of single-photon level light fields by several hundred nanometers in an optically thick cold gas is demonstrated, while preserving quantum entanglement with a remotely stored matter excitation. These are essential elements for long-distance quantum telecommunication, fundamental tests of quantum mechanics, and applications in secure communication and computation. The first trapping and laser cooling of Thorium-229 ions are described. Thorium-229 nuclear electric quadrupole moment is revealed by hyperfine spectroscopy of triply charged Thorium-229 ions. A system to search for the isomer nuclear transition in Thorium-229 is developed and tested with the excitation of a forbidden electronic transition at 717 nm. Direct excitation of the nuclear transition with laser light would allow for an extremely accurate clock and a sensitive test bed for variations of fundamental physical constants, including the fine structure constant.