Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Spin Qubits"”.
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Decoherence and Dynamical Decoupling in Solid-State Spin Qubits
… is a study of the decoherence of a solid-state spin qubit, either that of a localized electron spin or a donor nucleus, caused by a nuclear spin bath relevant to semiconductor quantum computer architectures. In the presence of an external magnetic field and at low temperatures, the dominant …
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High-fidelity microwave control of single-atom spin qubits in silicon
… demonstration of the full operation of single-spin qubits in Si. Our qubits consist of the electron and nuclear spins of a single phosphorus atom, implanted in a Si substrate, and controlled by a gated nanostructure. We describe an experimental setup tailored to minimise electron temperature …
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Towards scalable solid-state spin qubits and quantum simulation of thermal states
… for exchange-coupled solid-state electronic spin qubits in arrays of gate-defined quantum dots. We start by demonstrating theoretically the existence of a discrete time crystal phase in finite Heisenberg spin chains. We present driving pulses that can be used to induce time crystalline …
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Microwave and optical control of sub-diffraction spin qubits in diamond at cryogenic temperatures
Efficient entanglement of negative nitrogen vacancy (NV) centers in diamond will bring us significantly closer to realizing a large scale quantum network, including the design and development of quantum computers. A central requirement for generating large-scale entanglement is a system that can be …
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RF instrumentation and system design for coherent control of anisotropic hyperfine-coupled electron/nuclear spin qubits
… of interest employs a local, isolated electron spin to coherently control nuclear spins. Coupled electron/nuclear spins are a promising candidate for QIP: nuclear spins are used for information storage and computation due to their long coherence times, while the electron is used as a spin …
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Quantum Information Processing with Color Center Qubits: Theory of Initialization and Robust Control
… we need a scalable quantum platform in which qubits are con trollable. Color centers provide controllable optically-active spin qubits within the coherence time limit. Moreover, the nearby nuclear spins have long coherence times suitable for quantum memories. In this thesis, I present a …
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Scalable creation of spin-photon interfaces for solid-state quantum information processing
… solid-state qubit due to its exceptional spin and optical properties. In this thesis, we develop high-yield, efficient spin-photon interfaces in diamond. In particular, we demonstrate a process that produces dielectic reflectors and photonic crystal nanobeam cavities directly on the …
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Split gate tunnel barriers in double top gated silicon metal-oxide-semiconductor nanostructures
… An immense amount of interest has grown in spin-based silicon quantum computers where an electron spin represents a quantum bit (qubit). Spin qubits in silicon are attractive because of their long coherence times due to the weak spin-orbit coupling of silicon and the ability to eliminate …
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Investigation of triphenylene-based radical-containing ligand bridges in mediating electronic spin coupling and sensing chemical analytes
… magnetic material, as they mediate strong spin exchange coupling between paramagnetic metals, and have potential for maintaining coherence at room temperature. In this thesis, the author explores ligand-mediated spin coupling and quantum properties of the tritopic radical bridge HXTP (HXTP …
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Nanoscale engineering of spin-based quantum devices in diamond
… quantum phase coherence in their electron spin degrees of freedom, available highfidelity control and readout at the single-spin level, and strong interactions with other quantum systems such as photons. In addition, color centers can be controllably created and their local environment …
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Protocols and Devices for Scalable Spin-Photon Quantum Networks
… in atomic memories; among which, solid state spin qubits in diamond are particularly promising candidates for memory storage in a quantum repeater network. However, experimental efforts thus far have been mainly stymied by the absence of efficient and scalable spin-photon interfaces. To …
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Components for quantum computing based on optical transitions in single quantum dots
… QDs to act as an interface between photonic and spin qubits is explored. Application of a time varying electric field is used to dynamically tune the QD energy levels, allowing the evolution of excitons confined within single QDs to be manipulated. Using this system a controlled phase rotation of …
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Coherent control of hyperfine-coupled electron and nuclear spins for quantum information processing
Coupled electron-nuclear spins are promising physical systems for quantum information processing: By combining the long coherence times of the nuclear spins with the ability to initialize, control, and measure the electron spin state, the favorable properties of each spin species are utilized. This …
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Dispersive Readout and Spin-State Spectroscopy of Industrially-Fabricated Silicon Quantum Dots
… focuses on reliable and scalable readout of spin qubits in gate-defined silicon complementary metal-oxide-semiconductor quantum dots. In particular, this thesis studies the spin states and Pauli spin blockade (PSB) physics of silicon quantum dots using scalable gate-based dispersive sensing …
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Analyzing Electronic Correlation Effects in Molecules and Semiconductor Point Defects from First Principles Beyond Density Functional Theory
… terms, which are crucial for the realization of spin qubits and for interpreting electron paramagnetic resonance experiments. Chapter 4 turns to the application of a multiconfigurational method to describe the electronic properties of a silicon vacancy in silicon carbide, a potential point-defect …
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Using Device Physics and Error Mitigation to Improve the Performance of Quantum Computers
… cannot address arbitrarily many error-corrected qubits). Therefore, improvements that include consideration of the underlying physics are paramount. To do this, we must reduce existing errors and understand how algorithms perform without error correction. In this dissertation, we provide …
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Fermionic Quantum Information in Surface Acoustic Waves
… a framework for general measurements of electron qubits and provided a design for a semiconductor device capable of performing positive-operator valued measures (POVMs). A POVM is a powerful measurement technique in quantum mechanics that allows quantum information to be manipulated in interesting …
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Quantum Computation With Electron Spins of Phosphorous Donors in Silicon
… of a silicon- based quantum computer in which qubits are represented by the spins of electrons bound to phosphorous donors in silicon. Encoding each qubit in terms of three neighboring donor electron spins, we can realize universal quantum gate operations with only the Heisenberg exchange …
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