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Full-Text Articles in Quantum Physics

Circulation Transfer Between Adjacent Target Bose-Einstein Condensates, Charles B. Henry May 2022

Circulation Transfer Between Adjacent Target Bose-Einstein Condensates, Charles B. Henry

Honors College Theses

We propose an atomtronic rotation sensor design that consists of an array of Bose-Einstein Condensates (BECs) that are confined in a double-target-array potential. The rotation sensor's purpose is to measure the speed of the rotating frame, with respect to the “fixed stars", the sensor rests in. The atomtronic system is an ultracold gas of sodium atoms that have been compressed by laser light into a thin quasi-2D horizontal plane and further confined in the horizontal plane by a double-target-array potential. A target BEC is a combination of disk BEC that is surrounded by a ring BEC. A double-target BEC is …


Ring Bose–Einstein Condensate Atomtronic Rotation Sensor, Oluwatobi I. Adeniji Jan 2022

Ring Bose–Einstein Condensate Atomtronic Rotation Sensor, Oluwatobi I. Adeniji

College of Graduate Studies: Theses & Dissertations

We propose a design for an atomtronic rotation sensor consisting of an array of Bose– Einstein condensates (BECs) confined in a double–target–array potential. The purpose of the sensor is to measure the rotation speed, ΩR, of the sensor’s rest frame with respect to the “fixed stars.” The atomtronic system consists of an ultracold gas of sodium atoms compressed, using laser light, into a thin horizontal sheet and subjected to a double–target– array potential within the horizontal plane. A “target” BEC consists of a disk–shaped condensate surrounded by a concentric ring–shaped condensate. A “double–target” BEC is two adjacent target …


Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature, Benjamin R. Eller Jan 2019

Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature, Benjamin R. Eller

College of Graduate Studies: Theses & Dissertations

We extend previous theoretical investigations of the creation of quantized circulation states by stirring Bose-Einstein condensates (BEC) confined in ``racetrack" potentials. The previous study, {\em Producing Smooth Flow in Atom Circuits by Stirring}, used the Gross-Pitaevskii equation (GPE), which is valid at $T=0$ K. Here we use a non-zero temperature model based on the Zaremba, Nikuni, Griffin (ZNG) theory to simulate stirring racetrack BECs. The two main goals of this thesis are 1) to understand the effects of temperature on the production of circulation and 2) to understand the mechanism by which the circulation is excited. We find that it …


Producing Smooth Flow In Atom Circuits By Stirring, Olatunde Oladehin Jan 2018

Producing Smooth Flow In Atom Circuits By Stirring, Olatunde Oladehin

College of Graduate Studies: Theses & Dissertations

We studied how smooth flow can be produced by stirring an ultracold atom circuit consisting of a gaseous Bose--Einstein condensate (BEC) confined in a ``racetrack'' potential. The racetrack potential was made up of two straight parallel channels of length L connected on both ends by semicircular channels of the same width and (energy) depth as the straightaways. We used the Gross--Pitaevskii equation to simulate the behavior of the BEC in this potential when stirred by a rectangular paddle at various speeds and barrier heights. We found that smooth flow could be produced and conducted a systematic study of the flow …


Developing Tools For A Precision Measurement Of Newton's Gravitational Constant Using Atom Interferometry, Elizabeth Ashwood May 2017

Developing Tools For A Precision Measurement Of Newton's Gravitational Constant Using Atom Interferometry, Elizabeth Ashwood

Honors College Theses

We propose a new atom interferometry scheme for making a precision measurement of Newton's Gravitational constant (Big G) using NASA's Cold-Atom Laboratory which is scheduled to be deployed to the International Space Station in 2017. The proposed interferometer consists of splitting a harmonically confined Bose-Einstein condensate into multiple pieces. In a perfect harmonic potential, all of the pieces come to rest at the same time, at which point the harmonic trap is turned off. These initially motionless condensate clouds then accumulate different phases due to the relative velocity they develop caused by the gravitational attraction of a nearby source mass. …


Stereographic Visualization Of Bose-Einstein Condensate Clouds To Measure The Gravitational Constant, Ed Wesley Wells Jan 2016

Stereographic Visualization Of Bose-Einstein Condensate Clouds To Measure The Gravitational Constant, Ed Wesley Wells

College of Graduate Studies: Theses & Dissertations

This thesis describes a set of tools that can be used for the rapid design of atom interferometer schemes suitable for measuring Newton's Universal Gravitation constant also known as "Big G". This tool set is especially applicable to Bose--Einstein--condensed systems present in NASA's Cold Atom Laboratory experiment to be deployed to the International Space Station in 2017. These tools include a method of approximating the solutions of the nonlinear Schrödinger or Gross--Pitaevskii equation (GPE) using the Lagrangian Variational Method. They also include a set of software tools for translating the approximate solutions of the GPE into images of the optical …


Dipole Bound Excited States Of Polycyclic Aromatic Hydrocarbons Containing Nitrogen And Their Relation To The Interstellar Medium, Mallory L. Theis Apr 2014

Dipole Bound Excited States Of Polycyclic Aromatic Hydrocarbons Containing Nitrogen And Their Relation To The Interstellar Medium, Mallory L. Theis

Honors College Theses

Polycyclic aromatic hydrocarbons (PAHs) are the most abundant type of molecule present in the interstellar medium (ISM). It has been hypothesized that nitrogen replacement within a ring is likely for PAHs present in the ISM. Additionally, electrons, protons, and hydrogen atoms are readily added to or removed from PAHs creating a truly diverse set of chemistries in various interstellar regions. The presence of a nitrogen within a PAH (called a PANH herein) that is additionally dehydrogenated leads to a neutral radical with a large dipole moment. It has recently been shown through the use of high-level quantum chemical computations for …