Quantum Dots In Two-Dimensional Tungsten Diselenide

This work focuses on the investigation of single and double quantum dots in two-dimensional transition metal dichalcogenide tungsten diselenide (WSe_2) as a means to evaluate the valley degree of freedom as a potential qubit and ambipolar tungsten diselenide monolayers as single photon sources. Gate-defined quantum dots in monolayer and bilayer WSe_2 were fabricated and characterized. Single dot devices are gated from above and below the WSe_2 to accumulate a hole gas. Temperature dependence of Coulomb-blockade peak height is consistent with single-level transport. Excited-state transport in the quantum dot is shown for both monolayer and bilayer devices. Magnetic field dependence of the excited states in the bilayer devices provides a lower bound for g factors. Ambipolar monolayer WSe_2 is integrated into a double dot P-N junction device. Design considerations for double dot devices are discussed. Early measurements of double dot devices show features in the current possibly consistent with transport through double dots