Single Atom Delivery into a Bottle Beam Trap Using an Optical Conveyor Belt and Quantum Coherent Gain in a Matterwave Transistor
The work of this dissertation falls into two broad categories. In the first part, I describe
loading a single atom from a reservoir into a blue-detuned crossed vortex bottle beam trap using a
dynamic 1D optical lattice. The lattice beams are frequency chirped using acousto-optic modulators, which causes the lattice to move along its axial direction and behave like an optical conveyor
belt. A stationary lattice is initially loaded with approximately 6000 atoms from a reservoir, and
the conveyor belt transports them 1.1 mm from the reservoir to a bottle beam trap, where a single
atom is loaded via light-assisted collisions. Photon counting data confirm that an atom can be
delivered and loaded into the bottle beam trap 13.1 % of the time.
In part II, I describe a theory and experiment in the field of atomtronics that displays a
coherent gain mechanism for a triple-well matterwave transistor oscillator. I start with a wellestablished semi-classical description of an atomtronic transistor but model the system using a
many-body formalism. The quantum model predicts interesting physics when the atoms flowing
through the transistor have sufficiently low enough temperatures such that the motional state of a
dipole oscillating BEC, placed in the transistor itself, couples atom transitions between high lying
transistor energy eigenstates. In this regime, the coupling gives rise to a new gain mechanism
that increases the flux of matterwaves flowing out of the transistor system, compared to when the
coupling is absent. Our experiments suggest that the gain mechanism is coherent and increases the
spread of matterwave energy that flows out of the transistor.