Quantum Electrodynamics with Superconducting Circuits: Effects of Dissipation and Fluctuations

Quantum Electrodynamics with Superconducting Circuits: Effects of Dissipation and Fluctuations PDF Author: Stephan André
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Languages : en
Pages :

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Quantum Electrodynamics with Superconducting Circuits: Effects of Dissipation and Fluctuations

Quantum Electrodynamics with Superconducting Circuits: Effects of Dissipation and Fluctuations PDF Author: Stephan André
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Category :
Languages : en
Pages :

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Effects of Dissipation on Collective Behaviour in Circuit Quantum Electrodynamics

Effects of Dissipation on Collective Behaviour in Circuit Quantum Electrodynamics PDF Author: Felix Beat Fabian Nissen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Quantum Fluctuations and Dissipation in Ultra-thin Superconducting Films

Quantum Fluctuations and Dissipation in Ultra-thin Superconducting Films PDF Author: Heinrich Martin Jaeger
Publisher:
ISBN:
Category :
Languages : en
Pages : 434

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Modeling Classical Dynamics and Quantum Effects in Superconducting Circuit Systems

Modeling Classical Dynamics and Quantum Effects in Superconducting Circuit Systems PDF Author: Peter Groszkowski
Publisher:
ISBN:
Category : Casimir effect
Languages : en
Pages : 152

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In recent years, superconducting circuits have come to the forefront of certain areas of physics. They have shown to be particularly useful in research related to quantum computing and information, as well as fundamental physics. This is largely because they provide a very flexible way to implement complicated quantum systems that can be relatively easily manipulated and measured. In this thesis we look at three different applications where superconducting circuits play a central role, and explore their classical and quantum dynamics and behavior. The first part consists of studying the Casimir [Proc. K. Ned. Akad. Wet (1948)] and Casimir-Polder like [Physical Review 73, 4 (1948)]effects. These effects have been discovered in 1948 and show that under certain conditions, vacuum field fluctuations can mediate forces between neutral objects. In our work, we analyze analogous behavior in a superconducting system which consists of a stripline cavity with a DC-SQUID on one of its boundaries, as well as, in a Casimir-Polder case, a charge qubit coupled to the field of the cavity. Instead of a force, in the system considered here, we show that the Casimir and Casimir-Polder like effects are mediated through a circulating current around the loop of the boundary DC-SQUID. Using detailed analysis, we examine how the values of these currents change as we vary different physical circuit parameters. We show that for the set of physical parameters that can be easily obtained experimentally, the Casimir and Casimir-Polder currents can be of the order of 10^(-8) A and 10^(-13) A respectively. In the second part, we theoretically model an experiment which was performed by Britton Plourde's group at Syracuse University, and which studied the transient dynamics of a nonlinear superconducting oscillator, based on a capacitively shunted DC-SQUID. Such DC-SQUID oscillators are used in many areas of physics and engineering, for example, as building blocks of amplifiers or qubits, qubit couplers, or as sensitive magnetic field detectors. In many of these situations, their steady state behavior is often considered, while in the experiment performed at Syracuse, of specific interest, was the response of a DC-SQUID oscillator to a short radiation that only briefly excited the system. In this thesis, we simulate this response at the experimental temperature, by numerically solving a set of classical stochastic differential equations that mimic the behavior of the circuit. This is done for different settings of the flux that is threaded through the DC-SQUID as well as different input pulse amplitudes. Furthermore, we briefly outline just how these kinds of brief excitations could be useful when applied in flux measurement protocols. We find that our simulations show good agreement with the experimentally obtained data. The final part considered in this thesis, looks at the dynamics of a qubit coupled to a measuring probe, which is modeled as a harmonic oscillator. An example superconducting circuit, that could be used to implement such a setup, consists of a flux qubit inductively coupled to a DC-SQUID. This measurement scenario has already been explored in [Phys. Rev. B 78, 5 (2008)], but there, the authors only consider very short interaction times between the DC-SQUID and the qubit. Here, in contrast, we concentrate our efforts on studying the evolution of qubit as the measurement takes place, by solving the corresponding Lindblad master equation, but over longer measurement times. This is done by calculating the measurement induced dephasing rate of the qubit, as well as, discussing its sometimes present effective relaxation, in regimes where the measurement is considered to not be quantum non-demolition (QND). Finally, we briefly explore how well a potentially complicated evolution of the qubit can be approximated as a very simple Kraus map.

Physics and Applications of the Josephson Effect

Physics and Applications of the Josephson Effect PDF Author: Antonio Barone
Publisher: Wiley-VCH
ISBN:
Category : Science
Languages : en
Pages : 568

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Cover -- Contents -- CHAPTER 1 Weak Superconductivity8212; Phenomenological Aspects -- 146;1 Macroscopic Quantum System -- 146;2 Coupled Superconductors -- 146;3 Single Electron Tunneling -- 146;4 Josephson Equations -- 146;5 Magnetic Field Effects -- 146;6 Barrier Free Energy -- 146;7 Electrodynamics of the Josephson Junction -- 146;8 Other Josephson Structures -- CHAPTER 2 Microscopic Theory -- 1 Tunneling Hamiltonian Formalism -- 2 General Expression for the Total Current -- 3 Tunneling Current for Constant Voltage -- 4 Expressions of Iqpi44; Iqp44; IJ144; IJ2 -- 5 Tunneling Current in the B46;C46;S46; Approximation -- 6 The 34;cos w34; Problem -- CHAPTER 3 Magnitude and Temperature Dependence of the Critical Current -- 346;1 Josephson Current for V61;0 -- 346;2 B46;C46;S46; Approximation -- 346;3 Strong Coupling Effects -- 346;4 Effects of Paramagnetic Impurities -- 346;5 Measurement Techniques -- CHAPTER 4 34;Small34; Junctions in a Magnetic Field -- 446;1 Josephson Penetration Depth -- 446;2 Small Junctions -- 446;3 Uniform Tunneling Current Distribution -- 446;4 Nonuniform Tunneling Current Density -- CHAPTER 5 Large Junctions8212;Static Self45;Field Effects -- 546;1 Approximate Analysis -- 546;2 Analysis of Owen and Scalapino -- 546;3 Effects of the Junction Geometrical Configuration -- CHAPTER 6 Voltage Current Characteristics -- 646;1 V45;I Curves of Various Weak Links -- 646;2 Resistively Shunted Junction Model58; Autonomous Case -- 646;3 Current Biased Tunneling Junction -- 646;4 Effects of Thermal Fluctuations -- CHAPTER 7 Other Superconducting Weak Link Structures -- 746;1 Metal Barrier Junctions -- 746;2 Semiconducting Barrier Junctions -- 746;3 Bridge45;Type Junctions -- 746;4 Point Contact Weak Links -- CHAPTER 8 Device Fabrication Technology -- 846;1 Josephson Tunneling Junctions -- 846;2 Junction Electrodes -- 846;3 Oxide Barriers -- 846;4 Junction Patterning -- 846;5 Simple Procedures for Preparing Oxide Barrier Junctions -- 846;6 Semiconductor Barriers -- 846;7 Bridge45;Type Weak Links -- 846;8 Point Contact Structures -- CHAPTER 9 Resonant Modes In Tunneling Structures -- 946;1 Josephson Junction as a Transmission Line -- 946;2 Resonant Modes for Low Q Junctions -- 946;3 Junction of Infinite Length -- 946;4 Nonuniform Current Density Distribution -- CHAPTER 10 Fluxon Dynamics -- 1046;1 The Sine Gordon Equation -- 1046;2 Nonlinear Standing Waves on a Rectangular Junction -- 1046;3 Effects of Losses and Bias -- 1046;4 Zero Field Steps -- 1046;5 Perturbative Analysis of Fluxon Dynamics -- 1046;6 Effects of Flux Flow on D46;C46; Voltage45;Current Characteristics -- 1046;7 Two Dimensional Junctions -- CHAPTER 11 High Frequency Properties and Applications of the Josephson Effect -- 1146;1 Simple Voltage Source Model -- 1146;2 Tunneling Junctions in External Microwave Radiation -- 1146;3 Current Source Model -- 1146;4 Emission of Radiation -- 1146;5 Detection of Radiation -- 1146;6 Parametric Amplification -- 1146;7 The Determina.

Fundamentals and Frontiers of the Josephson Effect

Fundamentals and Frontiers of the Josephson Effect PDF Author: Francesco Tafuri
Publisher: Springer Nature
ISBN: 3030207269
Category : Technology & Engineering
Languages : en
Pages : 859

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Book Description
This book provides a comprehensive and up-to-date description of the Josephson effect, a topic of never-ending interest in both fundamental and applied physics. In this volume, world-renowned experts present the unique aspects of the physics of the Josephson effect, resulting from the use of new materials, of hybrid architectures and from the possibility of realizing nanoscale junctions. These new experimental capabilities lead to systems where novel coherent phenomena and transport processes emerge. All this is of great relevance and impact, especially when combined with the didactic approach of the book. The reader will benefit from a general and modern view of coherent phenomena in weakly-coupled superconductors on a macroscopic scale. Topics that have been only recently discussed in specialized papers and in short reviews are described here for the first time and organized in a general framework. An important section of the book is also devoted to applications, with focus on long-term, future applications. In addition to a significant number of illustrations, the book includes numerous tables for comparative studies on technical aspects.

Quantum Processes and Measurement

Quantum Processes and Measurement PDF Author: Claude Fabre
Publisher: Cambridge University Press
ISBN: 1108477771
Category : Science
Languages : en
Pages : 315

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Book Description
A self-contained presentation of the theory of quantum processes, quantum evolution and the experimental methods for quantum measurement.

Casimir Physics

Casimir Physics PDF Author: Diego Dalvit
Publisher: Springer Science & Business Media
ISBN: 364220287X
Category : Science
Languages : en
Pages : 465

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Book Description
Casimir effects serve as primary examples of directly observable manifestations of the nontrivial properties of quantum fields, and as such are attracting increasing interest from quantum field theorists, particle physicists, and cosmologists. Furthermore, though very weak except at short distances, Casimir forces are universal in the sense that all material objects are subject to them. They are thus also an increasingly important part of the physics of atom-surface interactions, while in nanotechnology they are being investigated not only as contributors to ‘stiction’ but also as potential mechanisms for actuating micro-electromechanical devices. While the field of Casimir physics is expanding rapidly, it has reached a level of maturity in some important respects: on the experimental side, where most sources of imprecision in force measurements have been identified as well as on the theoretical side, where, for example, semi-analytical and numerical methods for the computation of Casimir forces between bodies of arbitrary shape have been successfully developed. This book is, then, a timely and comprehensive guide to the essence of Casimir (and Casimir-Polder) physics that will have lasting value, serving the dual purpose of an introduction and reference to the field. While this volume is not intended to be a unified textbook, but rather a collection of largely independent chapters written by prominent experts in the field, the detailed and carefully written articles adopt a style that should appeal to non-specialist researchers in the field as well as to a broader audience of graduate students.

New Trends in Superconducting Circuit Quantum Electrodynamics

New Trends in Superconducting Circuit Quantum Electrodynamics PDF Author: Matteo Mariantoni
Publisher:
ISBN: 9783832295530
Category : Integrated circuits
Languages : en
Pages : 383

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Dissipation-induced Enhancement of Quantum Fluctuations

Dissipation-induced Enhancement of Quantum Fluctuations PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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