Quantum electrodynamics in superconducting artificial atoms

Quantum electrodynamics in superconducting artificial atoms PDF Author: Igor Diniz
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Book Description
Cette thèse porte sur deux problèmes théoriques d'électrodynamique quantique en circuits supraconducteurs. Nous avons d'abord étudié les conditions d'obtention du couplage fort entre un résonateur et une distribution continue d'émetteurs élargie de façon inhomogène. Le développement de ce formalisme est fortement motivé par les récentes propositions d'utiliser des ensembles de degrés de liberté microscopiques pour réaliser des mémoires quantiques. En effet, ces systèmes bénéficient du couplage collectif au résonateur, tout en conservant les propriétés de relaxation d'un seul émetteur. Nous discutons l'influence de l'élargissement inhomogène sur l'existence et les propriétés de cohérence des pics polaritoniques obtenus dans le régime de couplage fort. Nous constatons que leur cohérence dépend de façon critique de la forme de la distribution et pas uniquement de sa largeur. En tenant compte de l'élargissement inhomogène, nous avons pu simuler avec une grande précision de nombreux résultats expérimentaux pionniers sur un ensemble de centres NV. La modélisation s'est révélée un outil puissant pour obtenir les propriétés des ensembles de spins couplés à un résonateur. Nous proposons également une méthode originale de mesure de l'état de qubits Josephson fondée sur un SQUID DC avec une inductance de boucle élevée. Ce système est décrit par un atome artificiel avec des niveaux d'énergie en forme de diamant où nous définissons les qubits logique et ancilla couplés entre eux par un terme Kerr croisé. En fonction de l'état du qubit logique, l'ancilla est couplée de manière résonante ou dispersive au résonateur, ce qui provoque un contraste important dans l'amplitude du signal micro-onde transmis par le résonateur. Les simulations montrent que cette méthode originale peut être plus rapide et peut aussi avoir une plus grande fidélité que les méthodes actuellement utilisées dans la communauté des circuits supraconducteurs.

Quantum electrodynamics in superconducting artificial atoms

Quantum electrodynamics in superconducting artificial atoms PDF Author: Igor Diniz
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

Get Book Here

Book Description
Cette thèse porte sur deux problèmes théoriques d'électrodynamique quantique en circuits supraconducteurs. Nous avons d'abord étudié les conditions d'obtention du couplage fort entre un résonateur et une distribution continue d'émetteurs élargie de façon inhomogène. Le développement de ce formalisme est fortement motivé par les récentes propositions d'utiliser des ensembles de degrés de liberté microscopiques pour réaliser des mémoires quantiques. En effet, ces systèmes bénéficient du couplage collectif au résonateur, tout en conservant les propriétés de relaxation d'un seul émetteur. Nous discutons l'influence de l'élargissement inhomogène sur l'existence et les propriétés de cohérence des pics polaritoniques obtenus dans le régime de couplage fort. Nous constatons que leur cohérence dépend de façon critique de la forme de la distribution et pas uniquement de sa largeur. En tenant compte de l'élargissement inhomogène, nous avons pu simuler avec une grande précision de nombreux résultats expérimentaux pionniers sur un ensemble de centres NV. La modélisation s'est révélée un outil puissant pour obtenir les propriétés des ensembles de spins couplés à un résonateur. Nous proposons également une méthode originale de mesure de l'état de qubits Josephson fondée sur un SQUID DC avec une inductance de boucle élevée. Ce système est décrit par un atome artificiel avec des niveaux d'énergie en forme de diamant où nous définissons les qubits logique et ancilla couplés entre eux par un terme Kerr croisé. En fonction de l'état du qubit logique, l'ancilla est couplée de manière résonante ou dispersive au résonateur, ce qui provoque un contraste important dans l'amplitude du signal micro-onde transmis par le résonateur. Les simulations montrent que cette méthode originale peut être plus rapide et peut aussi avoir une plus grande fidélité que les méthodes actuellement utilisées dans la communauté des circuits supraconducteurs.

Control and Readout of a Superconducting Artificial Atom

Control and Readout of a Superconducting Artificial Atom PDF Author: Romeo Bianchetti
Publisher: Sudwestdeutscher Verlag Fur Hochschulschriften AG
ISBN: 9783838111797
Category :
Languages : en
Pages : 164

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Book Description
Cavity quantum electrodynamics (CQED) features all unique characteristics of quantum mechanics, studying the strong interaction of single photons and atoms. The implementation of artificial superconducting atoms in high quality transmission line cavities realizes such a CQED setup in a solid state environment. This opens the field of quantum optics to embedded devices. Furthermore, the relatively simple fabrication of these devices makes them a promising candidate for the realization of a quantum information processor. In this architecture, macroscopic quantum circuits act as effective two- and three-level systems (qubits and qutrits) by employing the large non-linearity of a Josephson junction. They strongly couple to single photons in a one-dimensional superconducting cavity which inhibits radiative decay for the contained fragile states and at the same time acts as a readout device.

A V-shape Superconducting Artificial Atom for Circuit Quantum Electrodynamics

A V-shape Superconducting Artificial Atom for Circuit Quantum Electrodynamics PDF Author: Etienne Dumur
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This thesis focuses on the experimental realisation of an artificial atom with a V-shape energy level diagram.Inspired by trapped-ion experiments, we theoretically predict an ultra fast and high fidelity quantum nondestructive readout of qubit state by using the V-shape artificial atom in a circuit quantum electrodynamicsarchitecture.To realise this experiment, we have developed an experimental setup to perform transmission measurementsof our superconducting quantum circuits by heterodyne technique at very low temperatures (30mK) and verylow signal amplitude (fW). We also implemented a hardware and software environment enabling multi-tonespectroscopies and time-resolved measurements in order to control the quantum state of the artificial atomand the coherent field in the resonator. In addition, in order to optimise the experiment circuits we havecharacterised quarterwave microwave resonators made from aluminium and epitaxial rhenium thin films.The original quantum device is fabricated by two inductively coupled transmons. When the couplinginductance is of the order of the Josephson inductance, we observe “in-phase” and “out-of-phase” oscillatingmodes of the superconducting phase across the junctions. The energy spectrum of the system, measured bytwo-tone spectroscopy, is magnetic flux dependent. It is precisely described by our theoretical model leadingto an accurate determination of the circuit parameters. Because of their anharmonicity, in the low-energylimit, the two modes can be considered as two-level systems called qubits. At zero magnetic field, it hasbeen observed that the two qubits become coupled only by a cross-anharmonicity. This has been revealed,through three-tone spectroscopy, by a conditional frequency shift as large as 115MHz of one qubit transitiondepending on the other qubit state. All these experimental results demonstrate a V-shape energy diagram forour artificial atom which paves the way to an original and high performance read-out.

International Symposium on Mathematics, Quantum Theory, and Cryptography

International Symposium on Mathematics, Quantum Theory, and Cryptography PDF Author: Tsuyoshi Takagi
Publisher: Springer Nature
ISBN: 981155191X
Category : Technology & Engineering
Languages : en
Pages : 275

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Book Description
This open access book presents selected papers from International Symposium on Mathematics, Quantum Theory, and Cryptography (MQC), which was held on September 25-27, 2019 in Fukuoka, Japan. The international symposium MQC addresses the mathematics and quantum theory underlying secure modeling of the post quantum cryptography including e.g. mathematical study of the light-matter interaction models as well as quantum computing. The security of the most widely used RSA cryptosystem is based on the difficulty of factoring large integers. However, in 1994 Shor proposed a quantum polynomial time algorithm for factoring integers, and the RSA cryptosystem is no longer secure in the quantum computing model. This vulnerability has prompted research into post-quantum cryptography using alternative mathematical problems that are secure in the era of quantum computers. In this regard, the National Institute of Standards and Technology (NIST) began to standardize post-quantum cryptography in 2016. This book is suitable for postgraduate students in mathematics and computer science, as well as for experts in industry working on post-quantum cryptography.

Quantum Computing

Quantum Computing PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 030947969X
Category : Computers
Languages : en
Pages : 273

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Book Description
Quantum mechanics, the subfield of physics that describes the behavior of very small (quantum) particles, provides the basis for a new paradigm of computing. First proposed in the 1980s as a way to improve computational modeling of quantum systems, the field of quantum computing has recently garnered significant attention due to progress in building small-scale devices. However, significant technical advances will be required before a large-scale, practical quantum computer can be achieved. Quantum Computing: Progress and Prospects provides an introduction to the field, including the unique characteristics and constraints of the technology, and assesses the feasibility and implications of creating a functional quantum computer capable of addressing real-world problems. This report considers hardware and software requirements, quantum algorithms, drivers of advances in quantum computing and quantum devices, benchmarks associated with relevant use cases, the time and resources required, and how to assess the probability of success.

Superconducting Devices in Quantum Optics

Superconducting Devices in Quantum Optics PDF Author: Robert Hadfield
Publisher: Springer
ISBN: 3319240919
Category : Computers
Languages : en
Pages : 256

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Book Description
This book presents the basics and applications of superconducting devices in quantum optics. Over the past decade, superconducting devices have risen to prominence in the arena of quantum optics and quantum information processing. Superconducting detectors provide unparalleled performance for the detection of infrared photons in quantum cryptography, enable fundamental advances in quantum optics, and provide a direct route to on-chip optical quantum information processing. Superconducting circuits based on Josephson junctions provide a blueprint for scalable quantum information processing as well as opening up a new regime for quantum optics at microwave wavelengths. The new field of quantum acoustics allows the state of a superconducting qubit to be transmitted as a phonon excitation. This volume, edited by two leading researchers, provides a timely compilation of contributions from top groups worldwide across this dynamic field, anticipating future advances in this domain.

Fluctuating Nonlinear Oscillators

Fluctuating Nonlinear Oscillators PDF Author: Mark Dykman
Publisher: Oxford University Press
ISBN: 019969138X
Category : Mathematics
Languages : en
Pages : 446

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Book Description
The book provides a unifying insight into a broad range of phenomena displayed by vibrational systems of current interest. The chapters complement each other to give an account of the major fundamental results and applications in quantum information, condensed matter physics, and engineering.

Waveguide Quantum Electrodynamics with Superconducting Qubits

Waveguide Quantum Electrodynamics with Superconducting Qubits PDF Author: Bharath Kannan
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Experiments utilizing quantum optics have progressed rapidly in last few decades, particularly in the context of quantum computation, simulation, and communication. Early work in this field focused on implementations of cavity quantum electrodynamics (QED), where atoms, either natural or artificial, are strongly coupled to the confined photonic modes of cavities. However, in recent years, achieving strong coupling between atoms and itinerant photons has also gained significant interest for its applications in quantum networking. To this end, many atomic platforms are attempting to realize the waveguide QED architecture: atoms that interact with the continua of propagating photonic modes within a waveguide.

Exploring the Quantum

Exploring the Quantum PDF Author: Serge Haroche
Publisher: OUP Oxford
ISBN: 0191523240
Category : Science
Languages : en
Pages : 616

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Book Description
The counter-intuitive aspects of quantum physics have been long illustrated by thought experiments, from Einstein's photon box to Schrödinger's cat. These experiments have now become real, with single particles - electrons, atoms, or photons - directly unveiling the strange features of the quantum. State superpositions, entanglement and complementarity define a novel quantum logic which can be harnessed for information processing, raising great hopes for applications. This book describes a class of such thought experiments made real. Juggling with atoms and photons confined in cavities, ions or cold atoms in traps, is here an incentive to shed a new light on the basic concepts of quantum physics. Measurement processes and decoherence at the quantum-classical boundary are highlighted. This volume, which combines theory and experiments, will be of interest to students in quantum physics, teachers seeking illustrations for their lectures and new problem sets, researchers in quantum optics and quantum information.

Towards a Scalable Quantum Computing Platform in the Ultrastrong Coupling Regime

Towards a Scalable Quantum Computing Platform in the Ultrastrong Coupling Regime PDF Author: Thi Ha Kyaw
Publisher: Springer
ISBN: 3030196585
Category : Computers
Languages : en
Pages : 116

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Book Description
This thesis devotes three introductory chapters to outlining basic recipes for constructing the quantum Hamiltonian of an arbitrary superconducting circuit, starting from classical circuit design. Since a superconducting circuit is one of the most promising platforms for realizing a practical quantum computer, anyone who is starting out in the field will benefit greatly from this introduction. The second focus of the introduction is the ultrastrong light-matter interaction (USC), where the latest developments are described. This is followed by three main research works comprising quantum memory in USC; scaling up the 1D circuit to a 2D lattice configuration; creation of Noisy Intermediate-Scale Quantum era quantum error correction codes and polariton-mediated qubit-qubit interaction. The research work detailed in this thesis will make a major contribution to the development of quantum random access memory, a prerequisite for various quantum machine learning algorithms and applications.​