dc.description.abstract | An exciting frontier in quantum information science is the creation and manipulation of
bottom-up quantum systems that are built and controlled one by one. For the past 30
years, we have witnessed signi cant progresses in harnessing strong atom- eld interactions
for critical applications in quantum computation, communication, simulation, and metrology.
By extension, we can envisage a quantum network consisting of material nodes coupled
together with in nite-dimensional bosonic quantum channels. In this context, there
has been active research worldwide to achieve quantum optical circuits, for which single
atoms are wired by freely-propagating single photons through the circuit elements. For all
these systems, the system-size expansion with atoms and photons results in a fundamental
pathologic scaling that linearizes the very atom- eld interaction, and signi cantly limits
the degree of non-classicality and entanglement in analog atom- eld quantum systems for
atom number N 1.
The long-term motivation of this MSc thesis is (i) to discover new physical mechanisms
that extend the inherent scaling behavior of atom- eld interactions and (ii) to
develop quantum optics toolkits that design dynamical gauge structures for the realization
of lattice-gauge-theoretic quantum network and the synthesis of novel quantum optically
gauged materials. The basic premise is to achieve the strong coupling regime for a quantum
many-body material system interacting with the quantized elds of an optical cavity. Our
laboratory e ort can be described as the march towards \many-body QED," where optical
elds acquire some properties of the material interactions that constrain their dynamical
processes, as with quantum eld theories. While such an e ort currently do not exist elsewhere,
we are convicted that our work will become an essential endeavor to enable cavity
quantum electrodynamics (QED) in the bona- de regime of quantum many-body physics
in this entanglement frontier.
In this context, I describe an example in Chapter 2 that utilizes strong RydbergRydberg
interactions to design dynamical gauge structures for the quantum square ice
models. Quantum
uctuations driven by cavity-mediated in nite-range interaction stabilize
the quantum-gauged system into a long-range entangled quantum spin liquid that may
be detected through the time-ordered photoelectric statistics for photons leaking out of the
cavity. Fractionalized \spinon" and \vison" excitations can be manipulated for topological
quantum computation, and the emergent photons of arti cial QED in our lattice gauge
theoretic system can be directly measured and studied.
The laboratory challenge towards strongly coupled cavity Rydberg polaritons encompasses
three daunting research milestones that push the technological boundaries beyond of the state-of-the-arts. In Chapter 3, I discuss our extreme-high-vacuum chamber (XHV)
cluster system that allows the world's lowest operating vacuum environment P ' 10
Torr for an ultracold AMO experiment with long background-limited trap lifetimes. In
Chapter 4, I discuss our ultrastable laser systems stabilized to the ultra-low-expansion
optical cavities. Coupled with a scalable eld-programmable-gate-array (FPGA) digitalanalog
control system, we can manipulate arbitrarily the phase-amplitude relationship of
several dozens of laser elds across 300 nm to 1550 nm at mHz precision. In Chapter 5,
we discuss the quantum trajectory simulations for manipulating the external degrees of
freedom of ultracold atoms with external laser elds. Electrically tunable liquid crystal
lens creates a dynamically tunable optical trap to move the ultracold atomic gases over
long distance within the ultra-high-vacuum (UHV) chamber system.
In Chapter 6, I discuss our collaborative development of two science cavity platforms
{ the \Rydberg" quantum dot and the many-body QED platforms. An important development
was the research into new high-index IBS materials, where we have utilized our
low-loss optical mirrors for extending the world's highest cavity nesse F 500k! We discuss
the unique challenges of implementing optical cavity QED for Rydberg atoms, which
required tremendous degrees of electromagnetic shielding and eld control. Single-crystal
Sapphire structure, along with Angstrom-level diamond-turned Ti blade electrodes, is utilized
for the eld compensation and extinction by > 60 dB. Single-crystal PZTs on silica
V-grooves are utilized for the stabilization of the optical cavity with length uncertainty less
than 1=100 of a single nucleon, along with extreme level of vibration isolation in a XHV
environment. The capability to perform in-situ RF plasma cleaning allows the regeneration
of optical mirrors when coated with a few Cs atoms. Lastly but not the least, we combine
single-atom resolution quantum gas microscopy technique with superpixel holographic algorithm
to project arbitrary real-time recon gurable di raction-limited optical potential
landscapes for the preparation of low-entropy atom arrays. | en |