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Institution

Institute for Quantum Optics and Quantum Information

FacilityInnsbruck, Austria
About: Institute for Quantum Optics and Quantum Information is a facility organization based out in Innsbruck, Austria. It is known for research contribution in the topics: Quantum entanglement & Quantum information. The organization has 223 authors who have published 520 publications receiving 43470 citations. The organization is also known as: IQOQI Innsbruck.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors present a review of experiments in controlling and manipulating trapped atomic ions, together with the methods and tools that have enabled them, and provide an outlook on future directions in the field.
Abstract: Experimental progress in controlling and manipulating trapped atomic ions has opened the door for a series of proof-of-principle quantum simulations. This article reviews these experiments, together with the methods and tools that have enabled them, and provides an outlook on future directions in the field.

1,274 citations

Journal ArticleDOI
01 Dec 2005-Nature
TL;DR: The scalable and deterministic generation of four-, five-, six-, seven- and eight-particle entangled states of the W type with trapped ions are reported, which obtain the maximum possible information on these states by performing full characterization via state tomography, using individual control and detection of the ions.
Abstract: The generation, manipulation and fundamental understanding of entanglement lies at the very heart of quantum mechanics. Entangled particles are non-interacting but are described by a common wavefunction; consequently, individual particles are not independent of each other and their quantum properties are inextricably interwoven. The intriguing features of entanglement become particularly evident if the particles can be individually controlled and physically separated. However, both the experimental realization and characterization of entanglement become exceedingly difficult for systems with many particles. The main difficulty is to manipulate and detect the quantum state of individual particles as well as to control the interaction between them. So far, entanglement of four ions or five photons has been demonstrated experimentally. The creation of scalable multiparticle entanglement demands a non-exponential scaling of resources with particle number. Among the various kinds of entangled states, the 'W state' plays an important role as its entanglement is maximally persistent and robust even under particle loss. Such states are central as a resource in quantum information processing and multiparty quantum communication. Here we report the scalable and deterministic generation of four-, five-, six-, seven- and eight-particle entangled states of the W type with trapped ions. We obtain the maximum possible information on these states by performing full characterization via state tomography, using individual control and detection of the ions. A detailed analysis proves that the entanglement is genuine. The availability of such multiparticle entangled states, together with full information in the form of their density matrices, creates a test-bed for theoretical studies of multiparticle entanglement. Independently, 'Greenberger-Horne-Zeilinger' entangled states with up to six ions have been created and analysed in Boulder.

1,133 citations

Journal ArticleDOI
18 Jun 2008-Nature
TL;DR: Experiments show that just a few entangled trapped ions can be used to improve the precision of measurements, and if the entanglement in such systems can be scaled up to larger numbers of ions, simulations that are intractable on a classical computer might become possible.
Abstract: To process information using quantum-mechanical principles, the states of individual particles need to be entangled and manipulated. One way to do this is to use trapped, laser-cooled atomic ions. Attaining a general-purpose quantum computer is, however, a distant goal, but recent experiments show that just a few entangled trapped ions can be used to improve the precision of measurements. If the entanglement in such systems can be scaled up to larger numbers of ions, simulations that are intractable on a classical computer might become possible.

1,111 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reported the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits by investigating the coherence of up to 8 ions over time and observed a decay proportional to the square of the number of qubits.
Abstract: We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the number of qubits. The observed decay agrees with a theoretical model which assumes a system affected by correlated, Gaussian phase noise. This model holds for the majority of current experimental systems developed towards quantum computation and quantum metrology.

1,008 citations

Journal ArticleDOI
17 Jun 2004-Nature
TL;DR: Deterministic quantum-state teleportation between a pair of trapped calcium ions is reported, demonstrating unequivocally the quantum nature of the process.
Abstract: Teleportation of a quantum state encompasses the complete transfer of information from one particle to another. The complete specification of the quantum state of a system generally requires an infinite amount of information, even for simple two-level systems (qubits). Moreover, the principles of quantum mechanics dictate that any measurement on a system immediately alters its state, while yielding at most one bit of information. The transfer of a state from one system to another (by performing measurements on the first and operations on the second) might therefore appear impossible. However, it has been shown that the entangling properties of quantum mechanics, in combination with classical communication, allow quantum-state teleportation to be performed. Teleportation using pairs of entangled photons has been demonstrated, but such techniques are probabilistic, requiring post-selection of measured photons. Here, we report deterministic quantum-state teleportation between a pair of trapped calcium ions. Following closely the original proposal, we create a highly entangled pair of ions and perform a complete Bell-state measurement involving one ion from this pair and a third source ion. State reconstruction conditioned on this measurement is then performed on the other half of the entangled pair. The measured fidelity is 75%, demonstrating unequivocally the quantum nature of the process.

983 citations


Authors

Showing all 226 results

NameH-indexPapersCitations
Peter Zoller13473476093
Anton Zeilinger12563171013
Rainer Blatt8641933415
Markus Aspelmeyer6922421613
Rudolf Grimm6624621062
Thomas Jennewein6025015957
Ferdinand Schmidt-Kaler5928213900
Časlav Brukner5922812950
Hans J. Briegel5625120305
Christian F. Roos5613416415
Otfried Gühne5423711708
Tommaso Calarco531929077
Esteban Martínez5234910242
Rupert Ursin5217612560
Sylvain Gigan5023510514
Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20231
20224
202124
202019
201922
201817