Lost, but not forgotten: Extracting quantum information in noisy systems
Abstract: In this talk, we will mainly focus on noisy quantum trees: at each node of a tree, a received qubit unitarily interacts with fresh ancilla qubits, after which each qubit is sent through a noisy channel to a different node in the next level. Therefore, as the tree depth grows, there is a competition between the irreversible effect of noise and the protection against such noise achieved by delocalization of information.
JQI Researcher Awarded Distinguished Research Scientist Prize
JQI Research Scientist Grégory Moille has received the Distinguished Research Scientist Prize from the College of Computer, Mathematical and Natural Sciences at the University of Maryland. The award comes with a $5,000 prize and celebrates his research excellence.
Crystalline Topological Invariants in Invertible Fermionic States and Fractional Chern Insulators
Dissertation Committee Chair: Maissam Barkeshli
Committee:
Victor Galitski
Victor Yakovenko
Avik Dutt
Jonathan Rosenberg
Observation of string breaking on a (2+1)D Rydberg quantum simulator
Abstract: Fundamental forces of nature are described by gauge theories, and the interactions of matter with gauge fields lead to intriguing phenomena like the confinement of quarks in quantum chromodynamics. Separating a confined quark-anti-quark pair incurs an energy cost that grows linearly with their separation, eventually leading to the production of additional particles by an effect that is called string-breaking. In this talk, I will discuss how similar phenomenology can be probed using Rydberg atom arrays.
Quantum Vortices of Photons
Abstract: Vortices appear in optics as phase twists in the electromagnetic field resulting from light-matter interactions. Quantum vortices, characterized by phase singularities in the wavefunction, are typically associated with strongly interacting many-particle systems. However, the emergence of vortices through the effective interaction of light with itself, a phenomenon requiring strong optical nonlinearity, was previously limited to the classical regime until recent advancements.
Complexity-constrained quantum thermodynamics
Abstract: Irreversible quantum computation requires thermodynamic work. In principle, one can often evade work costs by implementing reversible transformations. In practice, complexity---the difficulty of realizing a quantum process---poses an obstacle: a realistic agent can perform only a limited number of gates and so not every reversible transformation. Hence an agent, if unable to complete a task unitarily, may expend work on an irreversible process, such as erasure, to finish the job.
Strongly correlated excitons in moiré semiconductors
Dissertation Committee Chair: Mohammad Hafezi
Committee:
Jay Deep Sau
You Zhou
Aaron Sternbach
Ian B. Spielman
Christopher Jarzynski (Dean’s representative)
Modeling Superconducting Circuits for Quantum Computing and Quantum Sensing Applications
Dissertation Committee Chair: Christopher J. Lobb
Committee:
Jacob M. Taylor
Victor M. Galitski
Saikat Guha
Alicia J. Kollar
Quantum codes as robust phases of matter
Abstract: There is a deep connection between quantum error correction and phases of matter for spatially local codes in finite dimensions. I will show how this analogy extends to more general settings: quantum codes with check soundness are absolutely stable phases of matter. These codes include constant-rate quantum low-density parity-check codes, which shows that the third law of thermodynamics is false: there exist absolutely stable phases of matter with constant entropy density at zero temperature.
Rapid quantum ground state preparation via dissipative dynamics
Abstract: Inspired by natural cooling processes, dissipation has become a promising approach for preparing low-energy states of quantum systems. However, the potential of dissipative protocols remains unclear beyond certain commuting Hamiltonians.