Mixed-Species Ion Chains for Quantum Networks

Simple item page
dc.contributor.advisorMonroe, Christopheren_US
dc.contributor.authorSosnova, Kseniaen_US
dc.contributor.departmentPhysicsen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2020-07-10T05:34:25Z
dc.date.available2020-07-10T05:34:25Z
dc.date.issued2020en_US
dc.description.abstractQuantum computing promises solutions to some of the world's most important problems that classical computers have failed to address. The trapped-ion-based quantum computing platform has a lot of advantages for doing so: ions are perfectly identical and near-perfectly isolated, feature long coherent times, and allow high-fidelity individual laser-controlled operations. One of the greatest remaining obstacles in trapped-ion-based quantum computing is the issue of scalability. The approach that we take to address this issue is a modular architecture: separate ion traps, each with a manageable number of ions, are interconnected via photonic links. To avoid photon-generated crosstalk between qubits and utilize advantages of different kinds of ions for each role, we use two distinct species - ¹⁷¹Yb⁺ as memory qubits and ¹³⁸Ba⁺ as communication qubits. The qubits based on ¹⁷¹Yb⁺ are defined within the hyperfine "clock" states characterized by a very long coherence time while ¹³⁸Ba⁺ ions feature visible-range wavelength emission lines. Current optical and fiber technologies are more efficient in this range than at shorter wavelengths. We present a theoretical description and experimental demonstration of the key elements of a quantum network based on the mixed-species paradigm. The first one is entanglement between an atomic qubit and the polarization degree of freedom of a pure single photon. We observe a value of the second-order correlation function g⁽²⁾(0) = (8.1 ± 2.3)⨉10⁻⁵ without background subtraction, which is consistent with the lowest reported value in any system. Next, we show mixed-species entangling gates with two ions using the Mølmer-Sørensen and Cirac-Zoller protocols. Finally, we theoretically generalize mixed-species entangling gates to long ion chains and characterize the roles of normal modes there. In addition, we explore sympathetic cooling efficiency in such mixed-species crystals. Besides these developments, we demonstrate new techniques for manipulating states within the D₃⸝₂-manifold of zero-nuclear-spin ions - a part of a protected qubit scheme promising seconds-long coherence times proposed by Aharon et al. in 2013. As a next step, we provide a detailed description of the protocols for three- and four-node networks with mixed species, along with a novel design for the third trap with in-vacuum optics to optimize light collection.en_US
dc.identifierhttps://doi.org/10.13016/jjsc-jlae
dc.identifier.urihttp://hdl.handle.net/1903/26198
dc.language.isoenen_US
dc.subject.pqcontrolledQuantum physicsen_US
dc.subject.pqcontrolledAtomic physicsen_US
dc.subject.pqcontrolledPhysicsen_US
dc.subject.pquncontrolledIon trapsen_US
dc.subject.pquncontrolledIon-Photon entanglementen_US
dc.subject.pquncontrolledModular quantum architectureen_US
dc.subject.pquncontrolledQuantum computingen_US
dc.subject.pquncontrolledQuantum informationen_US
dc.subject.pquncontrolledQuantum networksen_US
dc.titleMixed-Species Ion Chains for Quantum Networksen_US
dc.typeDissertationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Sosnova_umd_0117E_20620.pdf
Size:
11.83 MB
Format:
Adobe Portable Document Format
Download

Collections

UMD Theses and Dissertations
Physics Theses and Dissertations