School of Physics Undergraduate Research Option Theses
http://hdl.handle.net/1853/22064
Research Thesis Option for Physics MajorsSat, 19 Jun 2021 11:55:55 GMT2021-06-19T11:55:55ZFrustrated Magnetism and Searching For Quantum Spin Liquid Phases in Novel Materials
http://hdl.handle.net/1853/63824
Frustrated Magnetism and Searching For Quantum Spin Liquid Phases in Novel Materials
Bender, Darian Marie
In my research, I wish to classify and identify a possible Quantum Spin-Liquid (QSL) phase on novel quantum materials. Materials of interest include the two triangular lattice materials, Li4CoTeO6 and Li4NiTeO6, in which Ni and Co ions with effective spin-1 and spin-1/2 each occupy a triangular lattice. We performed thermodynamic and magnetization measurements which indicate a possible exotic magnetic ground-state in both
materials. We then performed elastic neutron scattering, providing additional evidence for exotic magnetism in these materials. Inelastic neutron scattering measurements are still necessary to probe the nature of the magnetic correlations and to confirm a QSL phase.
Another material of interest is the kagomé lattice material, KFe3(OH)6(SO4)2 (known as Fe-Jarosite). This material is a popular QSL.1, 2 Small crystals of Fe-Jarosite have been created by hydrothermal synthesis in Mourigal Lab, and preliminary measurements of
magnetization are in good agreement with known values.1, 3 Neutron scattering is required to study this material’s spin-dynamics, however, scattering is weak. Therefore, further synthesis attempts must be performed in order to increase the size of single-crystals of Fe-Jarosite from 2.6 mm to 1.0 cm.
http://hdl.handle.net/1853/63824Bender, Darian MarieIn my research, I wish to classify and identify a possible Quantum Spin-Liquid (QSL) phase on novel quantum materials. Materials of interest include the two triangular lattice materials, Li4CoTeO6 and Li4NiTeO6, in which Ni and Co ions with effective spin-1 and spin-1/2 each occupy a triangular lattice. We performed thermodynamic and magnetization measurements which indicate a possible exotic magnetic ground-state in both
materials. We then performed elastic neutron scattering, providing additional evidence for exotic magnetism in these materials. Inelastic neutron scattering measurements are still necessary to probe the nature of the magnetic correlations and to confirm a QSL phase.
Another material of interest is the kagomé lattice material, KFe3(OH)6(SO4)2 (known as Fe-Jarosite). This material is a popular QSL.1, 2 Small crystals of Fe-Jarosite have been created by hydrothermal synthesis in Mourigal Lab, and preliminary measurements of
magnetization are in good agreement with known values.1, 3 Neutron scattering is required to study this material’s spin-dynamics, however, scattering is weak. Therefore, further synthesis attempts must be performed in order to increase the size of single-crystals of Fe-Jarosite from 2.6 mm to 1.0 cm.Generation and Stability of Charged Toroidal Droplets
http://hdl.handle.net/1853/60372
Generation and Stability of Charged Toroidal Droplets
Aizenman, Aaron
In this project, we have determined the quantitative parameters governing the transition
phases of charged toroidal droplets. An instability reminiscent of the Saffman-Taylor
Instability (viscous fingers) has been observed when toroidal droplets are exposed to a
significantly high voltage source, but this is the only recorded development of this
instability in a three-dimensional situation (Alberto Fernandez-Nieves 2016). We created
a silicon oil environment of extremely high viscosity with aminopropyl terminated silicon
oil (ATSO) added to lower surface tension. We utilized surfactants to minimize the surface
tension between the inner and outer fluids to slow down the dynamics of the system
enough to give the surface a chance to reach equipotential, thus allowing us to test the
theories that currently exist in the field. In an attempt to disprove the possibility that this
was the Saffman-Taylor Instability, we also attempted viscosity inversion experiments.
These failed, thus giving us almost conclusive proof that this was indeed the
Saffman-Taylor Instability. By proving that this is indeed the Saffman-Taylor Instability,
we have also proven that this three-dimensional problem can be analyzed as a series of
two-dimensional problems. This approach vastly simplifies further calculations and
analysis of similar systems. A secondary focus of this project was to perfect a method of
automated generation of inherently unstable shapes in viscoelastic materials. By using a
novel method of 3D printing, the project attempted to increase the efficiency with which
we can generate samples for testing and observation while also adding uniformity and
consistency to the trials and experiments.
http://hdl.handle.net/1853/60372Aizenman, AaronIn this project, we have determined the quantitative parameters governing the transition
phases of charged toroidal droplets. An instability reminiscent of the Saffman-Taylor
Instability (viscous fingers) has been observed when toroidal droplets are exposed to a
significantly high voltage source, but this is the only recorded development of this
instability in a three-dimensional situation (Alberto Fernandez-Nieves 2016). We created
a silicon oil environment of extremely high viscosity with aminopropyl terminated silicon
oil (ATSO) added to lower surface tension. We utilized surfactants to minimize the surface
tension between the inner and outer fluids to slow down the dynamics of the system
enough to give the surface a chance to reach equipotential, thus allowing us to test the
theories that currently exist in the field. In an attempt to disprove the possibility that this
was the Saffman-Taylor Instability, we also attempted viscosity inversion experiments.
These failed, thus giving us almost conclusive proof that this was indeed the
Saffman-Taylor Instability. By proving that this is indeed the Saffman-Taylor Instability,
we have also proven that this three-dimensional problem can be analyzed as a series of
two-dimensional problems. This approach vastly simplifies further calculations and
analysis of similar systems. A secondary focus of this project was to perfect a method of
automated generation of inherently unstable shapes in viscoelastic materials. By using a
novel method of 3D printing, the project attempted to increase the efficiency with which
we can generate samples for testing and observation while also adding uniformity and
consistency to the trials and experiments.Model Selection in Gravitational Wave Astronomy
http://hdl.handle.net/1853/60349
Model Selection in Gravitational Wave Astronomy
Napier, Katherine
The several detections of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) and the Virgo detector are providing insights about the nature of gravity in our Universe [1]. As the number of detected gravitational waves increases, it will be necessary to employ computationally inexpensive methods to extract the parameters of the gravitational wave sources. This proof of concept study utilizes principal component analysis (PCA) to try to reduce the number of vectors needed to describe binary black hole (BBH) parameter space. The results of this study suggest that performing PCA on face-on BBH systems, those at zero degrees inclination, adds an unnecessary level of complexity. However, PCA is a beneficial method to apply to waveforms that are morphologically complex such as those from edge-on BBH systems, those at 90 degrees inclination. Running PCA on a catalog of specific waveforms in one area of parameter space can inform how to construct waveforms in other regions of parameter space. If these waveforms can be constructed to a high level of accuracy using only a few principal components (PCs), it will significantly reduce the computational cost associated with generating template waveforms. Instead of creating a waveform template for every parameter combination, the PCs can be used to construct waveforms from similar areas of parameter space.
http://hdl.handle.net/1853/60349Napier, KatherineThe several detections of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) and the Virgo detector are providing insights about the nature of gravity in our Universe [1]. As the number of detected gravitational waves increases, it will be necessary to employ computationally inexpensive methods to extract the parameters of the gravitational wave sources. This proof of concept study utilizes principal component analysis (PCA) to try to reduce the number of vectors needed to describe binary black hole (BBH) parameter space. The results of this study suggest that performing PCA on face-on BBH systems, those at zero degrees inclination, adds an unnecessary level of complexity. However, PCA is a beneficial method to apply to waveforms that are morphologically complex such as those from edge-on BBH systems, those at 90 degrees inclination. Running PCA on a catalog of specific waveforms in one area of parameter space can inform how to construct waveforms in other regions of parameter space. If these waveforms can be constructed to a high level of accuracy using only a few principal components (PCs), it will significantly reduce the computational cost associated with generating template waveforms. Instead of creating a waveform template for every parameter combination, the PCs can be used to construct waveforms from similar areas of parameter space.Bayesave Analysis Study on Recovering Waveform Complexity through Reconstructions
http://hdl.handle.net/1853/58497
Bayesave Analysis Study on Recovering Waveform Complexity through Reconstructions
Day, Brian M.
The field of gravitational wave astronomy is a means of observing the universe in a new way. Crucial to the success of this new astronomy is analyzing the data obtained from the Laser Interferometer Gravitational-Wave Observatory (LIGO). Gravitational waves are oscillations of spacetime that propagate to Earth. We can predict these waveforms using solutions of Einstein’s Equations from general relativity. There are several ways the LIGO scientific collaboration uses to detect signals. This thesis presents my work on one such method, Bayeswave analysis. Bayeswave analysis is one tool to process the data collected from the detectors. Bayeswave offers analysis on a potential event that is agnostic, in other words it is independent of theoretical predictions of the signal, due to it being a minimal assumption analysis and can be used to determine if the event is a signal, a glitch, or noise. Through the analysis, Bayeswave uses evidence values obtained from comparing signal, glitch, and noise models to determine what the event most likely is and produces reconstructions of both the signal and glitch models. This information can be used to further understand the event in the data. Although Bayeswave has shown to be able to accurately reconstruct simple waveforms, its ability to accurately reconstruct waveforms from systems with more complex initial parameters is not known. Therefore, this study is to determine if Bayeswave can accurately reconstruct known injected signals with varied initial parameter complexity. The ability for Bayeswave to reconstruct the more complex injected waveforms is gauged by analyzing the median overlap between the reconstruction and the injection as a function of signal-to-noise ratio (SNR), which is a gauge of how strong the signal is compared to background noise, for various inclination angles, the strain and frequency data as functions of time, and the residual strain of the reconstruction waveform when it is subtracted from the injected waveform as a function of time.
http://hdl.handle.net/1853/58497Day, Brian M.The field of gravitational wave astronomy is a means of observing the universe in a new way. Crucial to the success of this new astronomy is analyzing the data obtained from the Laser Interferometer Gravitational-Wave Observatory (LIGO). Gravitational waves are oscillations of spacetime that propagate to Earth. We can predict these waveforms using solutions of Einstein’s Equations from general relativity. There are several ways the LIGO scientific collaboration uses to detect signals. This thesis presents my work on one such method, Bayeswave analysis. Bayeswave analysis is one tool to process the data collected from the detectors. Bayeswave offers analysis on a potential event that is agnostic, in other words it is independent of theoretical predictions of the signal, due to it being a minimal assumption analysis and can be used to determine if the event is a signal, a glitch, or noise. Through the analysis, Bayeswave uses evidence values obtained from comparing signal, glitch, and noise models to determine what the event most likely is and produces reconstructions of both the signal and glitch models. This information can be used to further understand the event in the data. Although Bayeswave has shown to be able to accurately reconstruct simple waveforms, its ability to accurately reconstruct waveforms from systems with more complex initial parameters is not known. Therefore, this study is to determine if Bayeswave can accurately reconstruct known injected signals with varied initial parameter complexity. The ability for Bayeswave to reconstruct the more complex injected waveforms is gauged by analyzing the median overlap between the reconstruction and the injection as a function of signal-to-noise ratio (SNR), which is a gauge of how strong the signal is compared to background noise, for various inclination angles, the strain and frequency data as functions of time, and the residual strain of the reconstruction waveform when it is subtracted from the injected waveform as a function of time.