Transport of Bose-Einstein Condensates Through Two Dimensional Cavities

Transport of Bose-Einstein Condensates Through Two Dimensional Cavities PDF Author: Timo Hartmann
Publisher: Universitatsverlag Regensburg
ISBN: 9783868451191
Category :
Languages : en
Pages : 0

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Book Description
The recent experimental advances in manipulating ultra-cold atoms make it feasible to study coherent transport of Bose-Einstein condensates (BEC) through various mesoscopic structures. In this work the quasi-stationary propagation of BEC matter waves through two dimensional cavities is investigated using numerical simulations within the mean-field approach of the Gross-Pitaevskii equation. The focus is on the interplay between interference effects and the interaction term in the non-linear wave equation. One sees that the transport properties show a complicated behaviour with multi-stability, hysteresis and dynamical instabilities for non-vanishing interaction. Furthermore, the prominent weak localization effect, which is a robust interference effect emerging after taking a configuration average, is reduced and partially inverted for non-vanishing interaction.

Transport of Bose-Einstein Condensates Through Two Dimensional Cavities

Transport of Bose-Einstein Condensates Through Two Dimensional Cavities PDF Author: Timo Hartmann
Publisher: Universitatsverlag Regensburg
ISBN: 9783868451191
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
The recent experimental advances in manipulating ultra-cold atoms make it feasible to study coherent transport of Bose-Einstein condensates (BEC) through various mesoscopic structures. In this work the quasi-stationary propagation of BEC matter waves through two dimensional cavities is investigated using numerical simulations within the mean-field approach of the Gross-Pitaevskii equation. The focus is on the interplay between interference effects and the interaction term in the non-linear wave equation. One sees that the transport properties show a complicated behaviour with multi-stability, hysteresis and dynamical instabilities for non-vanishing interaction. Furthermore, the prominent weak localization effect, which is a robust interference effect emerging after taking a configuration average, is reduced and partially inverted for non-vanishing interaction.

Transport and Turbulence in Quasi-Uniform and Versatile Bose-Einstein Condensates

Transport and Turbulence in Quasi-Uniform and Versatile Bose-Einstein Condensates PDF Author: Gauthier Guillaume
Publisher: Springer Nature
ISBN: 3030549674
Category : Science
Languages : en
Pages : 177

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Book Description
Advancing the experimental study of superfluids relies on increasingly sophisticated techniques. We develop and demonstrate the loading of Bose-Einstein condensates (BECs) into nearly arbitrary trapping potentials, with a resolution improved by a factor of seven when compared to reported systems. These advanced control techniques have since been adopted by several cold atoms labs around the world. How this BEC system was used to study 2D superfluid dynamics is described. In particular, negative temperature vortex states in a two-dimensional quantum fluid were observed. These states were first predicted by Lars Onsager 70 years ago and have significance to 2D turbulence in quantum and classical fluids, long-range interacting systems, and defect dynamics in high-energy physics. These experiments have established dilute-gas BECs as the prototypical system for the experimental study of point vortices and their nonequilibrium dynamics. We also developed a new approach to superfluid circuitry based on classical acoustic circuits, demonstrating its conceptual and quantitative superiority over previous lumped-element models. This has established foundational principles of superfluid circuitry that will impact the design of future transport experiments and new generation quantum devices, such as atomtronics circuits and superfluid sensors.

Probing Two-Dimensional Quantum Fluids with Cavity Optomechanics

Probing Two-Dimensional Quantum Fluids with Cavity Optomechanics PDF Author: Yauhen Sachkou
Publisher: Springer Nature
ISBN: 3030527662
Category : Science
Languages : en
Pages : 161

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Book Description
Superfluid helium is a quantum liquid that exhibits a range of counter-intuitive phenomena such as frictionless flow. Quantized vortices are a particularly important feature of superfluid helium, and all superfluids, characterized by a circulation that can only take prescribed integer values. However, the strong interactions between atoms in superfluid helium prohibit quantitative theory of vortex behaviour. Experiments have similarly not been able to observe coherent vortex dynamics. This thesis resolves this challenge, bringing microphotonic techniques to bear on two-dimensional superfluid helium, observing coherent vortex dynamics for the first time, and achieving this on a silicon chip. This represents a major scientific contribution, as it opens the door not only to providing a better understanding of this esoteric quantum state of matter, but also to building new quantum technologies based upon it, and to understanding the dynamics of astrophysical superfluids such as those thought to exist in the core of neutron stars.

Nonlinear Localization, Controlled Transport and Collapse Suppression in Bose-Einstein Condensates

Nonlinear Localization, Controlled Transport and Collapse Suppression in Bose-Einstein Condensates PDF Author: Jasur Abdullaev
Publisher:
ISBN:
Category : Atoms
Languages : en
Pages : 216

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Book Description
This thesis includes theoretical studies regarding stability and manipulation of Bose-Einstein condensates (BECs) of ultra-cold atoms in 2D trapping geometry, as well as formation of steady states of exciton-polariton Bose-Einstein condensates created in solid states. We analyze and numerically model the dynamics and localization of the condensates using mean-field model. Chapter 1 contains an introduction to the physics of ultra-cold atom BEC and excitonpolariton BEC which provides a framework for the work presented in later chapters. In Chapter 2, we consider a method for achieving dynamically controllable transport of highly mobile matter-wave solitons in an ultra-cold atom BEC with attractive interparticle interaction loaded into a driven two-dimensional optical lattice. Our numerical analysis based on the mean-field model and the theory based on the effective particle approach demonstrate that fast, time-periodic rocking of the two-dimensional optical lattice enables efficient stabilization and manipulation of spatially localized matter wave packets via induced reconfigurable mobility channels. Chapter 3 consists of an investigation of the instability - collapse of a BEC with attractive interactions. In this chapter we explore the influence of an orbital angular momentum on the collapse of vortex-free elliptic clouds of Bose-Einstein condensates trapped in a radially symmetric harmonic potential or a rotating elliptic potential. The results of our analysis show that the number of trapped ultracold atoms corresponding to the collapse threshold can be radically increased for such rotating nonlinear matter waves in a radially harmonic trap. The results corresponding to a BEC cloud confined in a rotating elliptic trap show that the elongated stationary states can be parallel or perpendicular to the long axis of the trap and display bistable nature. In Chapter 4, we examine spatial localization and dynamical stability of Bose-Einstein condensates of exciton-polaritons in microcavities under the condition of off-resonant spatially inhomogeneous optical pumping both with and without a harmonic trapping potential. We employ the open-dissipative Gross-Pitaevskii model for describing an incoherently pumped polariton condensate coupled to an exciton reservoir. We reveal that spatial localization of the steady-state condensate occurs due to effective self-trapping created by the polariton flows, regardless of the presence of the external potential. A ground state of the polariton condensate with repulsive interactions between the quasiparticles represents a dynamically stable bright dissipative soliton. We also investigate the conditions for sustaining spatially localized structures, with nonzero angular momentum, in the form of single-charge vortices. Chapter 5 consider the existence of novel spatially localized states of exciton-polariton Bose-Einstein condensates in semiconductor microcavities with fabricated periodic inplane potentials. Our theory shows that, under the conditions of continuous nonresonant pumping, localization is observed for a wide range of optical pump parameters due to effective potentials self-induced by the polariton flows in the spatially periodic system. We show that the self-localization of exciton-polaritons in the lattice may occur both in the gaps and bands of the single-particle linear spectrum, and is dominated by the effects of gain and dissipation rather than the structured potential, in sharp contrast to the conservative condensates of ultra-cold alkali atoms.

Bose-Einstein Condensation in Two-dimensional Traps

Bose-Einstein Condensation in Two-dimensional Traps PDF Author: Juan Pablo Fernández
Publisher:
ISBN:
Category : Bose-Einstein condensation
Languages : en
Pages : 276

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Book Description


Bose-Einstein Condensation in Dilute Gases

Bose-Einstein Condensation in Dilute Gases PDF Author: C. J. Pethick
Publisher: Cambridge University Press
ISBN: 052184651X
Category : Science
Languages : en
Pages : 0

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Book Description
Since an atomic Bose-Einstein condensate, predicted by Einstein in 1925, was first produced in the laboratory in 1995, the study of ultracold Bose and Fermi gases has become one of the most active areas in contemporary physics. This book explains phenomena in ultracold gases from basic principles, without assuming a detailed knowledge of atomic, condensed matter, and nuclear physics. This new edition has been revised and updated, and includes new chapters on optical lattices, low dimensions, and strongly-interacting Fermi systems. This book provides a unified introduction to the physics of ultracold atomic Bose and Fermi gases for advanced undergraduate and graduate students, as well as experimentalists and theorists. Chapters cover the statistical physics of trapped gases, atomic properties, cooling and trapping atoms, interatomic interactions, structure of trapped condensates, collective modes, rotating condensates, superfluidity, interference phenomena, and trapped Fermi gases. Problems are included at the end of each chapter.

Simulating Collisions Between Two-Dimensional Bose-Einstein Condensates

Simulating Collisions Between Two-Dimensional Bose-Einstein Condensates PDF Author: Timothy Wood Jones
Publisher:
ISBN:
Category : Bose-Einstein condensation
Languages : en
Pages : 88

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Book Description


Universal Themes of Bose-Einstein Condensation

Universal Themes of Bose-Einstein Condensation PDF Author: Nick P. Proukakis
Publisher: Cambridge University Press
ISBN: 1108138624
Category : Science
Languages : en
Pages : 663

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Book Description
Following an explosion of research on Bose–Einstein condensation (BEC) ignited by demonstration of the effect by 2001 Nobel prize winners Cornell, Wieman and Ketterle, this book surveys the field of BEC studies. Written by experts in the field, it focuses on Bose–Einstein condensation as a universal phenomenon, covering topics such as cold atoms, magnetic and optical condensates in solids, liquid helium and field theory. Summarising general theoretical concepts and the research to date - including novel experimental realisations in previously inaccessible systems and their theoretical interpretation - it is an excellent resource for researchers and students in theoretical and experimental physics who wish to learn of the general themes of BEC in different subfields.

Universal Themes of Bose-Einstein Condensation

Universal Themes of Bose-Einstein Condensation PDF Author: Nick P. Proukakis
Publisher: Cambridge University Press
ISBN: 1107085691
Category : Science
Languages : en
Pages : 663

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Book Description
Covering general theoretical concepts and the research to date, this book demonstrates that Bose-Einstein condensation is a truly universal phenomenon.

Bose Einstein Condensates in Optical Cavities

Bose Einstein Condensates in Optical Cavities PDF Author: Aranya Bhattacherjee
Publisher: LAP Lambert Academic Publishing
ISBN: 9783845429168
Category :
Languages : en
Pages : 112

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Book Description
The Bose Statistics were first predicted by the Indian Physicist Satyendra Nath Bose in 1924. Later in 1925, Einstein extended the work of Bose to non-interacting particles.The resulting statistics that came out of the work of Bose and Einstein is known as Bose-Einstein Statistics. It took researchers and scientists nearly 70 years to create the first Bose-Einstein Condensate in the laboratory in 1995. Ever since the discovery of BEC, research in this field has flourished very rapidly both theoretically and experimentally. Discovery of BEC has initiated some new topics such as atom optics, atom interferometry, quantum computation, Cavity Quantum Electrodynamics of BEC, precision measurement, low dimensional physics etc.This book explores some of the exciting new developments in a field, which combines Bose-Einstein Condensates and Optical cavities.Particularly, we show how the transmission spectroscopy can be utilized to measure the properties of the BEC in the optical cavity.