In a new take on quantum logic spectroscopy, a sensitive spectroscopy method employing a Schrödinger cat state of motion is investigated. With sensitivity down to the single photon level, the new technique extends the range of transitions that can be investigate in the spectroscopy of atomic and molecular ions. The results of our work are published in the journal Nature Photonics.
Not only do optical fibers transmit information every day around the world at the speed of light, but they can also be harnessed for the transport of quantum information. In the current issue of Nature Photonics, a research team of Innsbruck physicists led by Rainer Blatt and Tracy Northup report how they have directly transferred the quantum information stored in an atom onto a particle of light. Such information could then be sent over optical fiber to a distant atom.
While several building blocks for a quantum computer have already been successfully tested in the laboratory, a network requires one additonal component: a reliable interface between computers and information channels. In the current issue of the journal Nature, physicists at the University of Innsbruck report the construction of an efficient and tunable interface for quantum networks.
The time evolution of a quantum system under the action of a Hamiltonian acting for a duration t can be simulated by a gate-based approach. Instead of trying to engineer the Hamiltonian of interest as it is done in the analog quantum simulation approach, the digital method is based on sequences of quantum gates that generate the same propagator as the Hamiltonian to be simulated for a given instance of time. By making use of the Trotter formula, very different Hamiltonians can be simulated with the same basic universal set of quantum gates as we demonstrated in an experiment with two to six ions.
A team of physicists at the University of Innsbruck, led by Philipp Schindler and Rainer Blatt, has been the first to demonstrate a crucial element for a future functioning quantum computer: repetitive error correction. This allows scientists to correct errors occurring in a quantum computer efficiently. The researchers have published their findings in the scientific journal Science.
Once more Innsbruck physicists go beyond the limits of what is currently possible in quantum computation
Quantum physicists from the University of Innsbruck have set another world record: They have achieved controlled entanglement of 14 quantum bits (qubits) and, thus, realized the largest quantum register that has ever been produced. With this experiment the scientists have not only come closer to the realization of a quantum computer but they also show surprising results for the quantum mechanical phenomenon of entanglement.
Austrian researchers realize a toolbox for open-system quantum simulation
Experimental physicists have put a lot of effort in isolating sensitive measurements from the disruptive influences of the environment. In an international first, Austrian quantum physicists have realized a toolbox of elementary building blocks for an open-system quantum simulator, where a controlled coupling to an environment is used in a beneficial way. This offers novel prospects for studying the behavior of highly complex quantum systems. The researchers have published their work in the scientific journal Nature.
The Innsbruck research group led by physicist Rainer Blatt suggests a fundamentally new architecture for quantum computation. In an international first, they have experimentally demonstrated quantum antennae, which enable the exchange of quantum information between two separate memory cells located on a computer chip. This offers new opportunities to build practical quantum computers. The researchers have published their work in the scientific journal Nature.
In an experiment carried out in 2009, our group has performed a quantum simulation of the Dirac equation using a single trapped ion and observed so called Zitterbewegung, a peculiar quivering motion of free relativistic quantum particles predicted by the Dirac equation. In a recent experiment we have implemented a more sophisticated quantum simulation, which made it possible to observe another counter-intuitive prediction of the Dirac equation: the Klein paradox.
The entanglement of quantum objects can take surprising forms. The quantum physicists at the University of Innsbruck, Prof. Rainer Blatt and Dr. Julio Barreiro, have investigated several facets of entanglement in four trapped ions and report their results in the journal Nature Physics. Their study promotes further developments towards quantum computing and a deeper understanding of the foundations of quantum mechanics.
Quantum Optics and Spectroscopy
Institut für Experimentalphysik
Universität Innsbruck
Technikerstrasse 25/4
A-6020 Innsbruck, Austria
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