Quantum information with optical photons in hybrid molecule-superconducting qubit system

2014 ◽  
Author(s):  
S. Das ◽  
S. Faez ◽  
A. S. Sørensen
Keyword(s):  
Quantum Information ◽  
Superconducting Qubit ◽  
Hybrid Molecule ◽  
Qubit System ◽  
Optical Photons

Quantum optics with nitrogen-vacancy centres in diamond

2017 ◽  
Author(s):  
Yiwen Chu ◽  
Mikhail D. Lukin
Keyword(s):  
Optical Properties ◽  
Quantum Information ◽  
Solid State ◽  
Quantum Optics ◽  
Quantum States ◽  
Nitrogen Vacancy ◽  
Common Theme ◽  
External Effects ◽  
Promising Candidate ◽  
Optical Photons

A common theme in the implementation of quantum technologies involves addressing the seemingly contradictory needs for controllability and isolation from external effects. Undesirable effects of the environment must be minimized, while at the same time techniques and tools must be developed that enable interaction with the system in a controllable and well-defined manner. This chapter addresses several aspects of this theme with regard to a particularly promising candidate for developing applications in both metrology and quantum information, namely the nitrogen-vacancy (NV) centre in diamond. The chapter describes how the quantum states of NV centres can be manipulated, probed, and efficiently coupled with optical photons. It also discusses ways of tackling the challenges of controlling the optical properties of these emitters inside a complex solid state environment.

scholarly journals Optimal collection of radiation emitted by a trapped atomic ensemble

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Árpád Kurkó ◽  
Peter Domokos ◽  
András Vukics ◽  
Thomas Bækkegaard ◽  
Nikolaj Thomas Zinner ◽  
...  
Keyword(s):  
Quantum Information ◽  
Density Distribution ◽  
Ground State ◽  
Cold Atoms ◽  
Information Storage ◽  
Atomic Ensemble ◽  
Normal Density ◽  
Atomic Ensembles ◽  
Optical Photons ◽  
Electronic Ground

AbstractTrapped atomic ensembles are convenient systems for quantum information storage in the long-lived sublevels of the electronic ground state and its conversion to propagating optical photons via stimulated Raman processes. Here we investigate a phase-matched emission of photons from a coherently prepared atomic ensemble. We consider an ensemble of cold atoms in an elongated harmonic trap with normal density distribution, and determine the parameters of paraxial optics to match the mode geometry of the emitted radiation and optimally collect it into an optical waveguide.

Phase control for entanglement preparation in two-qubit systems

2005 ◽  
Vol 5 (4&5) ◽  
pp. 364-379
Author(s):  
V.S. Malinovsky ◽  
I.R. Sola
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Quantum Control ◽  
Phase Control ◽  
Adiabatic Passage ◽  
Pulse Parameters ◽  
Qubit System ◽  
Phase Manipulation ◽  
Laser Control ◽  
Pi Pulses

The theory of Quantum Control is starting to lay bridges with the field of Quantum Information and Quantum Computation. Using key ideas of laser control of the dynamics by means of phase manipulation and adiabatic passage, we review laser schemes that allow entanglement preparation in a two-qubit system. The schemes are based on sequences that use four time-delayed pulses, with or without concerted decay, in or off resonance with the intermediate levels of the qubit space. We show how to control the fidelity and phase of the entanglement, as well as the sensitivity of the preparation to the different pulse parameters. In general the schemes provide an improvement in robustness and in the finesse of the control to phase, with respect to previously proposed schemes based on sequences of $\pi$ pulses.

scholarly journals Dynamics of entanglement and non-classical correlation for four-qubit GHZ state

2015 ◽  
Vol 13 (06) ◽  
pp. 1550044 ◽  
Author(s):  
P. Espoukeh ◽  
R. Rahimi ◽  
S. Salimi ◽  
P. Pedram
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Discord ◽  
Quantum Information Processing ◽  
Ghz State ◽  
Classical Correlation ◽  
Qubit System ◽  
The Many ◽  
Sudden Transition

Many-qubit entanglement is crucial for quantum information processing although its exploitation is hindered by the detrimental effects of the environment surrounding the many-qubit system. It is thus of importance to study the dynamics of general multipartite non-classical correlation, including but not restricted to entanglement, under noise. We did this study for four-qubit Greenberger–Horne–Zeilinga (GHZ) state under most common noises in an experiment and found that non-classical correlation is more robust than entanglement except when it is imposed to dephasing channel. Quantum discord presents a sudden transition in its dynamics for Pauli-X and Pauli-Y noises as well as Bell-diagonal states interacting with dephasing reservoirs and it decays monotonically for Pauli-Z and isotropic noises.

scholarly journals Entanglement of Two-Superconducting-Qubit System Coupled with a Fixed Capacitor

2011 ◽  
Vol 28 (5) ◽  
pp. 050308 ◽  
Author(s):  
Li-Jun Tian ◽  
Li-Guo Qin ◽  
Hong-Biao Zhang
Keyword(s):  
Superconducting Qubit ◽  
Qubit System

scholarly journals Graph Approach to Quantum Teleportation Dynamics

2020 ◽  
Vol 2 (3) ◽  
pp. 352-377
Author(s):  
Efrén Honrubia ◽  
Ángel S. Sanz
Keyword(s):  
Quantum Information ◽  
Quantum Teleportation ◽  
Entangled States ◽  
Quantum Channels ◽  
Qubit System ◽  
Alternative Approaches ◽  
Maximally Entangled States ◽  
Usual State ◽  
Vector Description ◽  
Direct Correspondence

Quantum teleportation plays a key role in modern quantum technologies. Thus, it is of much interest to generate alternative approaches or representations that are aimed at allowing us a better understanding of the physics involved in the process from different perspectives. With this purpose, here an approach based on graph theory is introduced and discussed in the context of some applications. Its main goal is to provide a fully symbolic framework for quantum teleportation from a dynamical viewpoint, which makes explicit at each stage of the process how entanglement and information swap among the qubits involved in it. In order to construct this dynamical perspective, it has been necessary to define some auxiliary elements, namely virtual nodes and edges, as well as an additional notation for nodes describing potential states (against nodes accounting for actual states). With these elements, not only the flow of the process can be followed step by step, but they also allow us to establish a direct correspondence between this graph-based approach and the usual state vector description. To show the suitability and versatility of this graph-based approach, several particular teleportation examples are examined in detail, which include bipartite, tripartite, and tetrapartite maximally entangled states as quantum channels. From the analysis of these cases, a general protocol is devised to describe the sharing of quantum information in presence of maximally entangled multi-qubit system.

scholarly journals Synchronization of optical photons for quantum information processing

2016 ◽  
Vol 2 (5) ◽  
pp. e1501772 ◽  
Author(s):  
Kenzo Makino ◽  
Yosuke Hashimoto ◽  
Jun-ichi Yoshikawa ◽  
Hideaki Ohdan ◽  
Takeshi Toyama ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
High Purity ◽  
Quantum Interference ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Arrival Times ◽  
Optical Photons ◽  
Storage Times ◽  
First Time

A fundamental element of quantum information processing with photonic qubits is the nonclassical quantum interference between two photons when they bunch together via the Hong-Ou-Mandel (HOM) effect. Ultimately, many such photons must be processed in complex interferometric networks. For this purpose, it is essential to synchronize the arrival times of the flying photons and to keep their purities high. On the basis of the recent experimental success of single-photon storage with high purity, we demonstrate for the first time the HOM interference of two heralded, nearly pure optical photons synchronized through two independent quantum memories. Controlled storage times of up to 1.8 μs for about 90 events per second were achieved with purities that were sufficiently high for a negative Wigner function confirmed with homodyne measurements.

scholarly journals Simulating the Kibble-Zurek mechanism of the Ising model with a superconducting qubit system

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ming Gong ◽  
Xueda Wen ◽  
Guozhu Sun ◽  
Dan-Wei Zhang ◽  
Dong Lan ◽  
...  
Keyword(s):  
Ising Model ◽  
Superconducting Qubit ◽  
Qubit System

QUANTUM INFORMATION PROCESSING IN AN ARRAY OF SUPERCONDUCTING TRANSMISSION LINE RESONATORS

2009 ◽  
Vol 07 (06) ◽  
pp. 1255-1267
Author(s):  
JIAN LI ◽  
JIAN ZOU ◽  
BIN SHAO
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Transmission Line ◽  
Quantum State ◽  
Quantum Information Processing ◽  
Quantum State Transfer ◽  
Superconducting Qubit ◽  
One Dimensional ◽  
Dimensional Array ◽  
State Transfer

We consider a one-dimensional array of superconducting transmission line resonators (TLRs). The TLRs are coupled by current-biased Josephson junctions, which act as tunable couplers between each two nearest TLRs, and a superconducting qubit is fabricated in the center of each TLR. We show that some important quantum information processing, such as quantum state transfer and preparation of remote entanglement, can be achieved in this system, and we also propose a scheme for generating the W-class states.

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