Optical Quantum Memories With Cold Atomic Ensembles
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Author | : Adrien Nicolas |
Publisher | : |
Total Pages | : 0 |
Release | : 2014 |
Genre | : |
ISBN | : |
Download Optical Quantum Memories with Cold Atomic Ensembles Book in PDF, Epub and Kindle
We present an experimental study of two optical quantum memory systems based on electromagnetically induced transparency (EIT) in cold cesium atoms.We explain the relevance of quantum memories for the development of large-scale quantum networks, we give a comprehensive theory of the EIT phenomenon and underline the role of relevant parameters regarding the implementation of quantum memories.The first system under study is prepared in a free-space magneto-optical trap. The main result of this thesis is the demonstration of the spatial multimode capability of this system at the quantum level. For this, we used Laguerre-Gaussian (LG) light beams, i.e. beams possessing a non-zero value of orbital angular momentum (OAM). In a first step, we showed that the orbital angular momentum of stored light pulses is preserved by the memory, deep in the single photon regime. In a second step, we encoded information in the orbital angular momentum state of a weak light pulse and defined a qubit using two LG beams of opposite helicities. We developed an original setup for the measurement of this OAM qubit and used it to characterize the action of the memory during the storage of such a light pulse. Our results show that the memory performs the quantum storage of such a qubit.The second system under study, also a cloud of cold atoms, has the specificity that the atoms are trapped optically in the vicinity of a nano-waveguide. This innovative design ensures a higher light-matter interaction and facilitates the interfacing of photons into and out of the memory. We describe the building of this setup and the first steps towards quantum memory implementations.
Author | : Dong-Sheng Ding |
Publisher | : Springer |
Total Pages | : 136 |
Release | : 2017-12-26 |
Genre | : Science |
ISBN | : 9811074763 |
Download Broad Bandwidth and High Dimensional Quantum Memory Based on Atomic Ensembles Book in PDF, Epub and Kindle
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 | : Bo Jing |
Publisher | : Springer Nature |
Total Pages | : 197 |
Release | : 2022-03-16 |
Genre | : Science |
ISBN | : 981190328X |
Download Quantum Network with Multiple Cold Atomic Ensembles Book in PDF, Epub and Kindle
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 | : Lucile Veissier |
Publisher | : |
Total Pages | : 136 |
Release | : 2013 |
Genre | : |
ISBN | : |
Download Quantum Memory Protocols in Large Cold Atomic Ensembles Book in PDF, Epub and Kindle
Quantum memories are an essential building block for quantum information science and in particular for the implementation of quantum communications across long distances. A quantum memory is defined as a system capable of storing and retrieving quantum states on-demand, such as quantum bits (qubits). Atomic ensembles are good candidates for this purpose because they enables strong light-matter coupling in case of a large number of atoms. Moreover, the collective effect, enhanced in the regime of large optical depth, can lead to storage efficiency close to unity. Thus, in this thesis, a large magneto-optical trap for cesium atoms is used as a atomic medium in order to implement a quantum memory protocol based on electromagnetically induced transparency (EIT). First, the EIT phenomenon is studied through a criterion for the discrimination between the EIT and the Autler-Townes splitting models. We then report on the implementation of an EIT-based memory for photonic qubits encoded in orbital angular momentum (OAM) of light. A reversible memory for Laguerre-Gaussian modes is implemented, and we demonstrate that the optical memory preserves the handedness of the helical structure at the single-photon level. Then, a full quantum state tomography of the retrieved OAM encoded qubits is performed, giving fidelities above the classical bound. This showed that our optical memory operates in the quantum regime. Finally, we present the implementation of the so-called DLCZ protocol in our ensemble of cold atoms, enabling the generation of heralded single photons. A homodyne detection setup allows us to realize the quantum tomography of the created photonic state.
Author | : Yaroslav Dudin |
Publisher | : |
Total Pages | : |
Release | : 2012 |
Genre | : Quantum communication |
ISBN | : |
Download Investigations of Memory, Entanglement, and Long-range Interactions Using Ultra-cold Atoms Book in PDF, Epub and Kindle
Long-term storage of quantum information has diverse applications in quantum information science. This work presents an experimental realization of quantum memories with lifetimes greater then 0.1 s. The memories are based on cold rubidium atoms confined in one-dimensional optical lattices. First realization of lattice-based quantum memory and entanglement between a light field and a spin wave is presented in Chapter II. Chapter III describes two different methods (two-photon and magnetic) of compensation for inhomogeneous differential light shifts between the memory levels due to optical trapping potentials, and demonstration of entanglement between a telecom-band light field and a light-shift compensated memory qubit. Highly excited Rydberg atoms present a unique platform for study of strongly correlated systems and quantum information, because of their enormous dipole moments and consequent strong, long-range interactions. In the experiment described in Chapter IV single collective Rydberg excitations are created in a cold atomic gas. After a variable storage period the excitations are converted into light. As the principal quantum number n of the Rydberg level is increased beyond ~ 70, no more than a single excitation is retrieved from the entire mesoscopic ensemble of atoms. In Chapter V, by spatially selective conversion of the spin wave into a light field, we demonstrate that Rydberg-level interactions create long-range correlations of collective atomic excitations. These results hold promise for studies of dynamics and disorder in many-body systems with tunable interactions and for scalable quantum information networks. Chapter VI presents initial observations of coherent many-body Rabi oscillations between the ground level and a Rydberg level using several hundred cold rubidium atoms. The strongly pronounced oscillations indicate a nearly complete excitation blockade of the entire mesoscopic ensemble by a single excited atom.
Author | : Yong Yu |
Publisher | : Springer Nature |
Total Pages | : 147 |
Release | : 2023-01-01 |
Genre | : Science |
ISBN | : 9811979391 |
Download Long Distance Entanglement Between Quantum Memories Book in PDF, Epub and Kindle
This book highlights novel research work done on cold atom-based quantum networks. Given that one of the main challenges in building the quantum network is the limited entanglement distribution distance, this book presents some state-of-the-art experiments in tackling this challenge and, for the first time, establishes entanglement between quantum memories via metropolitan-scale fiber transmission. This achievement is accomplished by cooperating high-efficiency cold quantum memories, low-loss quantum frequency conversion modules, and long-fiber phase-locking techniques. In the book, the scheme design, experimental setup, data analyses, and numerous technical details are given. Therefore, it suits a broad readership that includes all students, researchers, and technicians who work in quantum information sciences.
Author | : N. J. Cerf |
Publisher | : World Scientific |
Total Pages | : 629 |
Release | : 2007 |
Genre | : Science |
ISBN | : 1860948162 |
Download Quantum Information with Continuous Variables of Atoms and Light Book in PDF, Epub and Kindle
Quantum information describes the new field which bridges quantum physics and information science. The quantum world allows for completely new architectures and protocols. While originally formulated in continuous quantum variables, the field worked almost exclusively with discrete variables, such as single photons and photon pairs. The renaissance of continuous variables came with European research consortia such as ACQUIRE (Advanced Coherent Quantum Information Research) in the late 1990s, and QUICOV (Quantum Information with Continuous Variables) from 2000OCo2003. The encouraging research results of QUICOV and the new conference series CVQIP (Continuous Variable Quantum Information Processing) triggered the idea for this book. This book presents the state of the art of quantum information with continuous quantum variables. The individual chapters discuss results achieved in QUICOV and presented at the first five CVQIP conferences from 2002OCo2006. Many world-leading scientists working on continuous variables outside Europe also contribute to the book.
Author | : Michael Woodhouse |
Publisher | : |
Total Pages | : |
Release | : 2016 |
Genre | : |
ISBN | : |
Download Quantum Dot Ensembles as an Optical Quantum Memory Book in PDF, Epub and Kindle
Author | : Eiichi Hanamura |
Publisher | : Springer Science & Business Media |
Total Pages | : 241 |
Release | : 2007-07-04 |
Genre | : Science |
ISBN | : 3540684840 |
Download Quantum Nonlinear Optics Book in PDF, Epub and Kindle
This graduate-level textbook gives an introductory overview of the fundamentals of quantum nonlinear optics. It deals with the organization of radiation field, interaction between electronic system and radiation field, statistics of light, and mutual manipulation of light and matter. It also covers laser oscillation, dynamics of light, nonlinear optical response, and nonlinear spectroscopy, as well as ultrashort and ultrastrong laser pulse. In addition, latest results of the frontier of this science are presented. Problems and solutions help the reader to master and review the material.
Author | : Martin Suda |
Publisher | : Springer Science & Business Media |
Total Pages | : 204 |
Release | : 2006 |
Genre | : Science |
ISBN | : 9783540260707 |
Download Quantum Interferometry in Phase Space Book in PDF, Epub and Kindle
"Quantum Interferometry in Phase Space" is primarily concerned with quantum-mechanical distribution functions and their applications in quantum optics and neutron interferometry. In the first part of the book, the author describes the phase-space representation of quantum optical phenomena such as coherent and squeezed states. Applications to interferometry, e.g. in beam splitters and fiber networks, are also presented. In the second part of the book, the theoretical formalism is applied to neutron interferometry, including the dynamical theory of diffraction, coherence properties of superposed beams, and dephasing effects.