A quantum prediction as a collection of knowledge-restricted classical predictions
Authors: Billy Braasch and William K. Wootters
Phase diagram of the XXZ spin-1/2 model on the pyrochlore lattice and its relation to the Programmable Rydberg Atoms Simulator
The spin-1/2 nearest-neighbor XXZ model on the pyrochlore lattice is an iconic frustrated three-dimensional spin system with a rich phase diagram on the $\lambda$ axis, where $\lambda$ is the XXZ interaction anisotropy.
Many-body entanglement dynamics and computation in quantum systems with power-law interactions
Dissertation Committee Chair: Victor Galitski
Committee:
Alexey Gorshkov (co-advisor)
Brian Swingle (co-advisor)
Andrew Childs
Xiaodi Wu
New species of butterflies reported in topological crystalline states
The study of topological phases of matter and the invariants that define them has become a central pursuit of condensed matter physics. In particular, crystalline systems are known to host a large set of topological invariants, but the physical response properties associated to them are still not fully understood.
Lattice-Based Quantum Advantage from Rotated Measurements
Trapdoor claw-free functions are immensely valuable in cryptographic interactions between a classical client and a quantum server. Typically, a protocol has the quantum server prepare a superposition of two-bit strings of a claw and then measure it using Pauli-X or Z measurements.
Realization of an effective Mexican-hat band for ultracold atoms in a time-modulated optical lattice
Dissertation Committee Chair: Norbert Linke
Committee:
Trey Porto
Ian B. Spielman
Wendell T. Hill
Yanne K. Chembo
Spin chains, defects, and quantum wires for the quantum-double edge
Abstract: Non-Abelian defects that bind Majorana or parafermion zero modes are prominent in several topological quantum computation schemes. Underpinning their established understanding is the quantum Ising spin chain, which can be recast as a fermionic model or viewed as a standalone effective theory for the surface-code edge -- both of which harbor non-Abelian defects. We generalize these notions by deriving an effective Ising-like spin chain describing the edge of quantum-double topological order.
Exciton in Mott insulator
Recent optical probes have used excitons, electron-hole bound states, to probe correlated insulating phases of two-dimensional semiconducting materials. Motivated by these experiments, we investigate these composite particles involving Mott physics. In this talk, we will discuss the formalism of two types of Mott excitons: Intraband exciton with both charges from a single band Hubbard model, and interband exciton with only one charge in the Mott.
Continuous-variable quantum state designs: theory and applications
Quantum state and unitary $t$-designs play an important role in several applications, including tomography, randomized benchmarking, state discrimination, cryptography, sensing, and fundamental physics. In this work, we generalize the notion of state designs to infinite-dimensional, separable Hilbert spaces. We first prove that under the definition of continuous-variable (CV) state $t$-designs from [Comm. Math. Phys 326, 755-771 (2014)], no state designs exist for $t\geq2$. Similarly, we prove that no CV unitary $t$-designs exist for $t\geq 2$.
Multilevel atoms and molecules for quantum information applications
Abstract: While it can be useful in some cases to abstract away all but 2 levels of the atoms used for quantum computing, it should not be forgotten that these qubit hosts often have many levels capable of participating in processing tasks. These include long-lived states within hyperfine, Zeeman, and electronic-state structure in atoms, but extend to rotational, vibrational, and more exotic level landscapes if one considers molecules instead of just atoms. Given the effectively atom-limited regime in which many (possibly all) atomic processors currently operate,