Date of Award

5-12-2024

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics

Advisor(s)

Britton Plourde

Second Advisor

Ian Hosein

Keywords

Metamaterials;Quantum computing;Quantum information;Superconducting qubits

Subject Categories

Physical Sciences and Mathematics | Physics | Quantum Physics

Abstract

Circuit quantum electrodynamics (cQED) systems with superconducting qubits coupled to linear microwave resonators are a prominent platform for realizing scalable quantum information processors. Combining cQED architectures with multimode resonators leads to a broad set of applications for performing analog quantum simulation, implementing dense quantum memory, and generating multimode entangled states between physically distant qubits. Microwave resonators in cQED are typically formed from distributed transmission lines that exhibit conventional dispersion with harmonic mode spacing; in such systems, usually only a single resonant mode can be strongly coupled to a qubit. Superconducting metamaterial resonators comprised of lumped circuit elements can be designed to produce a left-handed dispersion that results in a dense mode structure in the typical frequency range for operating superconducting qubits, thus allowing for a qubit to couple strongly to multiple modes simultaneously. Forming these metamaterial structures into a ring with qubits coupled at certain points around the ring results in a multi-mode bus with a compact physical footprint. In this thesis, we present a review of the design and fabrication of superconducting left-handed metamaterial ring resonators. We show, through low temperature measurements, that when we couple two flux-tunable transmon qubits to such a ring resonator, the system shows extreme versatility in coupling parameters due to the unique wave structure of the modes in the ring. We measure and model the interactions between the qubits and the ring resonator modes, as well as the inter qubit entangling interactions mediated by the multimode system. We describe how this platform could be used to implement two-qubit gates and generate entanglement between physically distant qubits.

Access

Open Access

Download

Share

COinS