Physics Commons^™

Memory Capacity In A System Of Swelling Particles, David T. Keating

Physics

A system has the ability to store memory if one is able to write, retrieve, and erase information from it. Some systems are capable of storing multiple transient memories; with no noise in these systems, at long time, the memories degrade until one or two remain. The addition of noise to these systems can extend the retention of multiple memories, in some cases indefinitely [2, 3]. While this behavior was first observed in simulations of charge density waves, it has since appeared in other systems [1].

Past research has shown that sheared non-Brownian liquid suspensions of particles exhibit similar behavior …

Swarming Oscillators With Time-Delayed Interactions, Nicholas S. Blum

Physics

We investigate the role of delay in the collective dynamics of particles that swarm in space and possess an internal oscillatory degree of freedom, called swarmalators. Swarmalators were introduced recently by O’Keeffe, Hong, and Strogatz in Nature Communications 8, 1504 (2017). The addition of a time delay into the system of swarmalators was motivated by the biology of early embryonic development. This delay leads to a rich phenomenology, which includes two new collective states, which we call "semi-static crystal" and "boiling". In the semi-static crystal state, all particles in a cluster undergo decaying radial oscillations completely in phase with one …

The Structure Function Relationship Of Disordered Networks Using Young's Modulus And Floppy Modes, Melinda Grace Tajnai

Physics

Disordered networks may have the ability to store information that can be retrieved using a Young’s modulus measurement. The effect of the number of floppy modes a network has on the value of this Young’s modulus measurement is unknown. This experiment uses 28 networks consisting of 3D printed edges in a sliding frame to determine how the Young’s modulus of a network is related to the number of floppy modes.

Pseudo Power Law Statistics In A Jammed, Amorphous Solid, Jacob Brian Hass

Physics

Simulations have shown that in many solid materials, rearrangements within the solid obey power-law statistics. A connection has been proposed between these statistics and the ability of a system to reach a limit cycle under cyclic driving. We study experimentally a 2D jammed solid that reaches such a limit cycle. Our solid consists of microscopic plastic beads adsorbed at an oil-water interface and cyclically sheared by a magnetically driven needle. We track each particles trajectory in the solid to identify rearrangements. By associating particles both spatially and temporally, we can measure the extent of each rearrangement. We study specifically the …

Simulating The Electrical Properties Of Random Carbon Nanotube Networks Using A Simple Model Based On Percolation Theory, Roberto Abril Valenzuela

Physics

Carbon nanotubes (CNTs) have been subject to extensive research towards their possible applications in the world of nanoelectronics. The interest in carbon nanotubes originates from their unique variety of properties useful in nanoelectronic devices. One key feature of carbon nanotubes is that the chiral angle at which they are rolled determines whether the tube is metallic or semiconducting. Of main interest to this project are devices containing a thin film of randomly arranged carbon nanotubes, known as carbon nanotube networks. The presence of semiconducting tubes in a CNT network can lead to a switching effect when the film is electro-statically …

Elasticity Of Cylindrical Black Holes, Conrad Pearson

Physics

Black holes are regions of strong gravity, and are often regarded as behaving like drops of fluid. When this line of thought is applied to cylindrical black holes (black cylinders), a mapping can be made between known instabilities for black cylinders and ordinary fluid cylinders. However, this known correlation is increasingly less accurate for lower spatial dimensions, and I seek to correct this discrepancy in this thesis. By considering soft solids instead of pure fluids, elastic energy can be included, which brings us closer to a direct comparison. In improving this mapping, it becomes possible to better understand the behavior …

Spontaneous Parametric Down Conversion Of Photons Through Β-Barium Borate, Luke Horowitz

Physics

An apparatus for detecting pairs of entangled 405nm photons that have undergone Spontaneous Parametric Down Conversion through β-Barium Borate is described. By using avalanche photo-diodes to detect the low-intensity converted beam and a coincidence module to register coincident photons, it is possible to create an apparatus than can be used to perform quantum information experiments under a budget appropriate for an undergraduate physics lab.

Thermodynamic Effects Of A Local Bell State Projection Interaction In A One-Dimensional Dynamic Spin System, Nickolas H. Pilgram

Physics

No abstract provided.

Phase Transitions In Smectic Liquid Crystal Systems, John Van Atta, Josh Ziegler

Physics

Liquid crystal systems show strong responses to small changes in both temperature and electric field. Changing these conditions can result in phase shifts and other similar behaviors. We study several theoretical models of smectic liquid crystals. The ideas and notation are first developed in basic polynomial models used to describe liquid crystal systems dependent only on temperature. Specifically, smectic-C to smectic-A phase transitions are examined in a fourth-order polynomial model. The bifurcations in the nonlinear equations are shown to correspond to the phase transi- tions in the system. Similar analytic techniques are then applied to a more complex model, based …

Modeling The Field Control Of The Surface Electroclinic Effect And Its Impact On Smectic Layer Strain, Kara M. Zappitelli

Physics

Chiral, smectic liquid crystal molecules align in layers and can be controlled by the application of an electric field, yielding a variety of implications for the quality of liquid crystal (LC) displays. Both the bulk electroclinic effect (BECE) and surface electroclinic effect (SECE) impact the angle at which the molecules tilt with respect to the layer normal in different areas of a LC cell due to dipole interactions. Certain LC’s exhibit a continuous Sm-A* to Sm-C* transition, where the angles of the surface and bulk molecules change continuously with electric field strength. Other LC’s exhibit first order transitions where we …