JQI

Abstract: Building large-scale modular quantum computers and quantum networks require high fidelity, high efficiency, and long lifetime quantum memories [1]. Quantum memories are proposed to increase photon-mediatated matter-qubit entanglment rates by synchronizing photon interference between network nodes [2].

Abstract: Many-body fermionic systems can be simulated in a hardware-efficient manner using a fermionic quantum processor. Neutral atoms trapped in optical potentials can realize such processors, where non-local fermionic statistics are guaranteed at the hardware level. Implementing quantum error correction in this setup is however challenging, due to the atom-number superselection present in atomic systems, that is, the impossibility of creating coherent superpositions of different particle numbers.

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.

Dissertation Committee Chair: Maissam Barkeshli

Committee: 

Victor Galitski

Victor Yakovenko

Avik Dutt

Jonathan Rosenberg

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.

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. 

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.

Dissertation Committee Chair: Mohammad Hafezi

Committee: 

Jay Deep Sau

You Zhou

Aaron Sternbach

Ian B. Spielman

Christopher Jarzynski (Dean’s representative)