JQI

Abstract: We create honeycomb superlattice structures in TMD moiré materials as model systems to
study magnetism, electronic correlations and topology. In twisted MoTe 2 , we realize topological flat
bands that closely resemble the lowest Landau level but in the absence of an external magnetic field.
We present evidence for integer and fractional Chern states [1], which are the lattice analogues of
integer and fractional quantum Hall states at zero magnetic field. We further explore correlated states in

In this work we present fast constructions for the quantum Fourier transform and quantum integer multiplication, using few ancilla qubits compared to the size of the input. For the approximate QFT we achieve depth O(log n) using only n + O(n / log n) total qubits, by applying a new technique we call "optimistic quantum circuits." To our knowledge this is the first circuit for the AQFT with space-time product O(n log n), matching a known lower bound.

Dissertation Committee Chair: Prof. Mohammad Hafezi

Committee: 

Professor Kartik Srinivasan

Professor Yanne Chembo

Professor Carlos A. Rios Ocampo

Professor Miao Yu (Dean’s Representative)

Abstract: Optical microresonators can trap light within compact volumes at discrete resonant frequencies, and soliton microcombs have advanced the miniaturization of various comb systems. Thin-film silicon nitride (Si3N4) microresonators, fabricated using CMOS foundry techniques, possess high-Q factors and have demonstrated many applications towards photonic integration. However, this platform has traditionally struggled to support bright solitons due to its normal dispersion nature.

Tom Wong is an Assistant Professor of Physics at Creighton University, and recently completed two years serving in the National Quantum Coordination office at the White House Office of Science and Technology Policy where he coordinated workforce and outreach activities and international cooperation efforts in support of the National Quantum Initiative; during this time he was also on detail from the Department of Energy, where he was a Program Manager in the Office of Science’s Advanced Scientific Computing Research program.

Abstract: One hundred years after Heisenberg’s Uncertainty Principle, the question of how to make simultaneous measurements of noncommuting observables lingers. I will survey one hundred years of measurement
theory, which brings us to the point where we can formulate how to measure any set observables weakly and simultaneously and then concatenate such measurements continuously to determine what is

Abstract: From bio-physics to quantum simulators, many fields depend on sub-diffraction imaging of multiple point sources.

Reservoir engineering has become valuable for preparing and stabilizing quantum systems. Notably, it has enabled the demonstration of dissipatively stabilized Schrödinger’s cat qubits through engineered two-photon loss which are interesting candidates for bosonic error-corrected quantum computation. Reservoir engineering is however limited to simple operators often derived from weak low-order expansions of some native system Hamiltonians. In this talk, I will introduce a novel reservoir engineering approach for stabilizing multi-component Schrödinger’s cat states.

While the search for quantum advantage typically focuses on speedups in execution time, quantum algorithms also offer the potential for advantage in space complexity. Previous work has shown such advantages for data stream problems, in which elements arrive and must be processed sequentially without random access, but these have been restricted to specially-constructed problems [Le Gall, SPAA `06] or polynomial advantage [Kallaugher, FOCS `21]. We show an exponential quantum space advantage for the maximum directed cut problem.