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Articles 1 - 4 of 4
Full-Text Articles in Quantum Physics
Ring Bose–Einstein Condensate Atomtronic Rotation Sensor, Oluwatobi I. Adeniji
Ring Bose–Einstein Condensate Atomtronic Rotation Sensor, Oluwatobi I. Adeniji
Electronic Theses and 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
Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature, Benjamin R. Eller
Electronic Theses and 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
Producing Smooth Flow In Atom Circuits By Stirring, Olatunde Oladehin
Electronic Theses and 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 …
Stereographic Visualization Of Bose-Einstein Condensate Clouds To Measure The Gravitational Constant, Ed Wesley Wells
Stereographic Visualization Of Bose-Einstein Condensate Clouds To Measure The Gravitational Constant, Ed Wesley Wells
Electronic Theses and 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 …