Now showing items 1-20 of 25

• #### Antilocalization of Coulomb Blockade in a Ge/Si Nanowire ﻿

(American Physical Society (APS), 2014)
The distribution of Coulomb blockade peak heights as a function of magnetic field is investigated experimentally in a Ge/Si nanowire quantum dot. Strong spin-orbit coupling in this hole-gas system leads to antilocalization ...
• #### Carbon Nanotubes for Coherent Spintronics ﻿

(Elsevier Science Limited, 2010)
Carbon nanotubes bridge the molecular and crystalline quantum worlds, and their extraordinary electronic, mechanical and optical properties have attracted enormous attention from a broad scientific community. We review ...
• #### Coherent Spin Manipulation in an Exchange-Only Qubit ﻿

(American Physical Society, 2010)
Initialization, two-spin coherent manipulation, and readout of a three-spin qubit are demonstrated using a few-electron triple quantum dot. The three-spin qubit is designed to allow all operations for full qubit control ...
• #### Direct Graphene Growth on Insulator ﻿

(Wiley, 2011)
Fabrication of graphene devices is often hindered by incompatibility between the silicon technology and the methods of graphene growth. Exfoliation from graphite yields excellent films but is good mainly for research. ...
• #### Distinct Signatures for Coulomb Blockade and Aharonov-Bohm Interference in Electronic Fabry-Perot Interferometers ﻿

(American Physical Society, 2009)
Two distinct types of magnetoresistance oscillations are observed in two electronic Fabry-Perot interferometers of different sizes in the integer quantum Hall regime. Measuring these oscillations as a function of magnetic ...
• #### Dynamic Nuclear Polarization in Double Quantum Dots ﻿

(American Physical Society, 2010)
We theoretically investigate the controlled dynamic polarization of lattice nuclear spins in GaAs double quantum dots containing two electrons. Three regimes of long-term dynamics are identiﬁed, including the buildup of ...
• #### Dynamic Nuclear Polarization in the Fractional Quantum Hall Regime ﻿

(American Physical Society, 2010)
We investigate dynamic nuclear polarization in quantum point contacts (QPCs) in the integer and fractional quantum Hall regimes. Following the application of a dc bias, fractional plateaus in the QPC shift symmetrically ...
• #### Edge-State Velocity and Coherence in a Quantum Hall Fabry-Pérot Interferometer ﻿

(American Physical Society, 2009)
We investigate nonlinear transport in electronic Fabry-Pérot interferometers in the integer quantum Hall regime. For interferometers sufficiently large that Coulomb blockade effects are absent, a checkerboardlike pattern ...
• #### Electron–Nuclear Interaction in $^{13}C$ Nanotube Double Quantum Dots ﻿

(Nature Publishing Group, 2009)
For coherent electron spins, hyperfine coupling to nuclei in the host material can either be a dominant source of unwanted spin decoherence or, if controlled effectively, a resource enabling storage and retrieval of quantum ...
• #### Etching of Graphene Devices with a Helium Ion Beam ﻿

(American Chemical Society, 2009)
We report on the etching of graphene devices with a helium ion beam, including in situ electrical measurement during lithography. The etching process can be used to nanostructure and electrically isolate different regions ...
• #### Exchange Control of Nuclear Spin Diffusion in a Double Quantum Dot ﻿

(American Physical Society, 2010)
The influence of gate-controlled two-electron exchange on the relaxation of nuclear polarization in small ensembles $(N \sim 10^6)$ of nuclear spins is examined in a GaAs double quantum dot system. Waiting in the (2,0) ...
• #### Fast Sensing of Double-Dot Charge Arrangement and Spin State with a Radio-Frequency Sensor Quantum Dot ﻿

(American Physical Society, 2010)
Single-shot measurement of the charge arrangement and spin state of a double quantum dot are reported with measurement times down to 100 ns. Sensing uses radio-frequency reflectometry of a proximal quantum dot in the Coulomb ...
• #### Hole Spin Relaxation in Ge-Si Core-Shell Nanowire Qubits ﻿

(Nature Publishing Group, 2012)
Controlling decoherence is the biggest challenge in efforts to develop quantum information hardware. Single electron spins in gallium arsenide are a leading candidate among implementations of solid-state quantum bits, but ...
• #### Hyperpolarized Silicon Particles as In-vivo Imaging Agents ﻿

(2012-11-02)
This thesis describes the development of hyperpolarized silicon particles as a new type of magnetic resonance imaging (MRI) agent. Silicon particles are inexpensive, non-toxic, biodegradable, targetable, and have unique ...
• #### Interferometer-Based Studies of Quantum Hall Phenomena ﻿

(2012-11-19)
The fractional quantum Hall (FQH) effect harbors a wealth of unique phenomena, many of which remain mysterious. Of particular interest is the predicted existence of quasi-particles with unusual topological properties, ...
• #### A New Mechanism of Electric Dipole Spin Resonance: Hyperfine Coupling in Quantum Dots ﻿

(Institute of Physics, 2009)
A recently discovered mechanism of electric dipole spin resonance, mediated by the hyperfine interaction, is investigated experimentally and theoretically. The effect is studied using a spin-selective transition in a GaAs ...
• #### Precision Cutting and Patterning of Graphene with Helium Ions ﻿

(Institute of Physics, 2009)
We report nanoscale patterning of graphene using a helium ion microscope configured for lithography. Helium ion lithography is a direct-write lithography process, comparable to conventional focused ion beam patterning, ...
• #### Quantum Dots for Conventional and Topological Qubits ﻿

(2015-09-29)
This thesis presents a series of quantum dot studies, performed with an eye towards improved conventional and topological qubits. Chapters 1-3 focus on improved conventional (spin) qubits; Chapters 4-6 focus on the topological ...
• #### Quantum Dots in Gated Nanowires and Nanotubes ﻿

(2012-08-17)
This thesis describes experiments on quantum dots made by locally gating one-dimensional quantum wires. The first experiment studies a double quantum dot device formed in a Ge/Si core/shell nanowire. In addition to measuring ...
• #### Quantum Hall Conductance of Two-Terminal Graphene Devices ﻿

(American Physical Society, 2009)
Measurement and theory of the two-terminal conductance of monolayer and bilayer graphene in the quantum Hall regime are compared. We examine features of conductance as a function of gate voltage that allow monolayer, ...