Towards a Spin-Ensemble Quantum Memory for Superconducting Qubits PDF Download

Author: Cécile Grèzes
Publisher: Springer
ISBN: 3319215728
Category : Computers
Languages : en
Pages : 240

View

Book Description
This work describes theoretical and experimental advances towards the realization of a hybrid quantum processor in which the collective degrees of freedom of an ensemble of spins in a crystal are used as a multi-qubit register for superconducting qubits. A memory protocol made of write, read and reset operations is first presented, followed by the demonstration of building blocks of its implementation with NV center spins in diamond. Qubit states are written by resonant absorption of a microwave photon in the spin ensemble and read out of the memory on-demand by applying Hahn echo refocusing techniques to the spins. The reset step is implemented in between two successive write-read sequences using optical repumping of the spins.

Author: Dong-Sheng Ding
Publisher: Springer
ISBN: 9811074763
Category : Science
Languages : en
Pages : 136

View

Book Description
This thesis presents an experimental study of quantum memory based on cold atomic ensembles and discusses photonic entanglement. It mainly focuses on experimental research on storing orbital angular momentum, and introduces readers to methods for storing a single photon carried by an image or an entanglement of spatial modes. The thesis also discusses the storage of photonic entanglement using the Raman scheme as a step toward implementing high-bandwidth quantum memory. The storage of photonic entanglement is central to achieving long-distance quantum communication based on quantum repeaters and scalable linear optical quantum computation. Addressing this key issue, the findings presented in the thesis are very promising with regard to future high-speed and high-capacity quantum communications.

Author: Schneider, Andre
Publisher: KIT Scientific Publishing
ISBN: 3731510324
Category : Science
Languages : en
Pages : 170

View

Book Description
Quantum sensing is a vast and emerging field enabling in-situ studies of quantum systems and hence the development of quantum hybrid systems. This work creates the fundament of direct superconducting-magnetic hybrid systems by developing a local microwave sensing scheme and studying the influence of a static magnetic field on a superconducting qubit. Finally, a proof-of-principle hybrid system is demonstrated, which opens the path towards superconducting-magnetic quantum circuits.

Author: Giovanni Franco-Rivera
Publisher:
ISBN:
Category : Condensed matter
Languages : en
Pages : 0

View

Book Description
The properties of quantum spins diluted in non-magnetic crystals make them a promising candidatefor a quantum memory given their long coherence and relaxation times and their limited Hilbert space span by the electron and nuclear states of the spin Hamiltonian. In order to efficiently store and retrieve the quantum information from, let's say a superconducting qubit quantum processor, the coupling between systems is mediated by on-chip superconducting resonators that acts as a quantum bus. For this, a strong coupling between the spin quantum memory and electromagnetic mode of the superconducting resonator is needed. The results presented in this dissertation demonstrates the implementation of coupled photonic states of an on-chip superconducting resonator with a Gd3+ rare-earth ion hosted in a scheelite (CaWO4) crystal. Experiments probing the weakly coupled limit of the resonator mode with the electronuclear states of the 155,157Gd3+ isotopes diluted in CaWO4 crystal are shown. Highly sensitive field dependent cavity spectroscopy measurements showed the perturbation of the resonator properties, such as the cavity linewidth and resonance frequency. Information about the spin ensemble phase memory loss rate and coupling strength were obtained for the six observed resonances resulting from the hyperfine slitting of the Gd odd isotopes. Given the resonator microwave field distribution and carefully selecting the orientation of the static field relative crystallographic c-axis, we were able to detect highly forbidden electron spin resnonance (ESR) transitions. Additionaly, the strong coupling signal of the Gd3+ spin transition between the first and second excited state with the on-chip resonator mode is demonstrated. By analyzing the spectroscopic signal using the Dicke model that describes the interaction of photonic states with a large S spin the observed transitions were reproduced by numerical diagonalization of the spin-cavity Hamiltonian. Lastly the dynamics of the spin-cavity states were explored via pulsed ESR measurements by recording the cavity ring-down signal at different pulse lengths and drive powers. The presented results are only a first step into the exploration of the Gd3+ spin dynamics at millikelvin temperatures.

Author: Thi Ha Kyaw
Publisher: Springer
ISBN: 3030196585
Category : Computers
Languages : en
Pages : 116

View

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.​

Author: Hua Wu
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Quantum computing has been a new and challenging area of research since the concept was put forward in 1980s. A quantum computer is a computer that processes information encoded in systems that exhibit quantum properties and is proved in theory to be more powerful than classical computers. Various approaches to the implementation of the quantum computers have been studied over the decades, each of them having their own advantages and disadvantages in terms of the lifetime of the quantum information, processing time, and scalability of the implementation. Proposals for hybrid quantum processors are interesting because they benefit from the advantages of each comprising system, and thus providing a promising approach to a practical quantum computer. In this thesis, I demonstrate experimentally the principle of utilizing electron spin ensembles as a quantum memory for hybrid quantum processors. I demonstrate the storage and on-demand retrieval of multiple bits of quantum information into and from a single electron spin ensemble by applying magnetic field gradient pulses. I then study the coupling between an electron spin ensemble and a three-dimensional microwave cavity, in the aim of discussing the condition for the coherent information transfer between the excitations in solid-state matter and photons. As an alternative to the high power pulses in electron paramagnetic resonance (EPR), I study the possibility of controlling the electron spin states via adiabatic processes. I demonstrate the implementation of adiabatic geometric phase gates in electron spins and compare their performances to other phase gates achieved with microwave pulses in both simulation and experiment, verifying the robustness of the adiabatic gates against certain type of noises. Finally I present the simulation method developed for simulating the pulsed EPR experiments in this thesis, using a model more general than some currently-existing simulation packages.

Author: Matthew Reed
Publisher: Lulu.com
ISBN: 1304084868
Category : Science
Languages : en
Pages : 384

View

Book Description
Softcover version of 2013 Ph.D. thesis of Matthew David Reed presented to the Physics department of Yale University. Concerns the realization of quantum error correction in the circuit quantum electrodynamics architecture, a precursor to quantum computing.

Author: Bo Jing
Publisher: Springer Nature
ISBN: 981190328X
Category : Science
Languages : en
Pages : 197

View

Book Description
This book highlights the novel research in quantum memory networking, especially quantum memories based on cold atomic ensembles. After discussing the frontiers of quantum networking research and building a DLCZ-type quantum memory with cold atomic ensemble, the author develops the ring cavity enhanced quantum memory and demonstrates a filter-free quantum memory, which significantly improves the photon-atom entanglement. The author then realizes for the first time the GHZ-type entanglement of three separate quantum memories, a building block of 2D quantum repeaters and quantum networks. The author also combines quantum memories and time-resolved measurements, and reports the first multiple interference of three single photons with different colors. The book is of good reference value for graduate students, researchers, and technical personnel in quantum information sciences.

Author: Kristiaan De Greve
Publisher: Springer Science & Business Media
ISBN: 3319000748
Category : Computers
Languages : en
Pages : 159

View

Book Description
Towards Solid-State Quantum Repeaters: Ultrafast, Coherent Optical Control and Spin-Photon Entanglement in Charged InAs Quantum Dots summarizes several state-of-the-art coherent spin manipulation experiments in III-V quantum dots. Both high-fidelity optical manipulation, decoherence due to nuclear spins and the spin coherence extraction are discussed, as is the generation of entanglement between a single spin qubit and a photonic qubit. The experimental results are analyzed and discussed in the context of future quantum technologies, such as quantum repeaters. Single spins in optically active semiconductor host materials have emerged as leading candidates for quantum information processing (QIP). The quantum nature of the spin allows for encoding of stationary, memory quantum bits (qubits), and the relatively weak interaction with the host material preserves the spin coherence. On the other hand, optically active host materials permit direct interfacing with light, which can be used for all-optical qubit manipulation, and for efficiently mapping matter qubits into photonic qubits that are suited for long-distance quantum communication.

Author: Yoshiro Hirayama
Publisher: Springer Nature
ISBN: 9811666792
Category : Science
Languages : en
Pages : 352

View

Book Description
This book presents state-of-the-art research on quantum hybridization, manipulation, and measurement in the context of hybrid quantum systems. It covers a broad range of experimental and theoretical topics relevant to quantum hybridization, manipulation, and measurement technologies, including a magnetic field sensor based on spin qubits in diamond NV centers, coherently coupled superconductor qubits, novel coherent couplings between electron and nuclear spin, photons and phonons, and coherent coupling of atoms and photons. Each topic is concisely described by an expert at the forefront of the field, helping readers quickly catch up on the latest advances in fundamental sciences and technologies of hybrid quantum systems, while also providing an essential overview.