They linked concepts of quantum optics and condensed matter physics and show a direction to build a quantum computer which is immune against perturbations. The scientists have published their work in the journal Nature Physics.
Majorana fermions are then generated at both ends of the atomic chain. Graphics: H. Ritsch
Three years ago a research team led by Sebastian Diehl and Peter Zoller presented a completely new approach to engineer quantum states in many-body systems. They used a physical phenomenon that normally increases the degree of disorder in a system dramatically: dissipation. In classical physics dissipation is the concept that explains the production of heat through friction. Surprisingly, in quantum physics dissipation can also lead to order and a completely pure many-body state can be realized. This spring an Innsbruck research team, led by experimental physicist Rainer Blatt, demonstrated experimentally that by using dissipation certain quantum effects can be generated and intensified. By linking concepts of quantum optics and condensed matter physics, theoretical physicists from the Institute of Theoretical Physics of the University of Innsbruck and the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences have now pointed out a new direction of how dissipation may be used in another beneficial and promising way.
Immune against perturbations
In condensed matter physics a new concept to describe order in many-body systems has gained in importance recently: topological order. Two examples for topological phenomena are the quantum Hall effect, which was demonstrated in the 1980s, and the topological insulator, which behaves as an electrical insulator in its interior while permitting the transport of charges on its surface. Sebastian Diehl and Peter Zoller’s team of theoretical physicists now suggest realizing dissipation induced Majorana fermions in a quantum system. This topological phenomenon was named after the Italian physicist Ettore Majorana and describes particles that are their own anti-particles. “We show a new way of how Majorana fermions may be created in a controlled way in a quantum system,“ explains Sebastian Diehl. “For this purpose we use a dissipative dynamic that drives the system into this state in a targeted way and compels it back when affected by disturbances.” With this new approach Diehl and his team combine the advantages of dissipation and topological order - both concepts are highly robust against perturbations such as disorder. Therefore, their suggestion to create Majorana fermions in an atomic quantum wire is of high interest for experimental implementation. It may be used for building a quantum computer whose basic building blocks consist of Majorana fermions. In quantum wires atoms are confined to one-dimensional structures by optical lattices which are generated by laser beams: Majorana fermions are then generated at both ends of the atomic chain.
START awardee Sebastian Diehl and his research group have linked the knowledge of condensed matter physics and quantum mechanics. “We work at the interface between those two disciplines, which creates exciting new possibilities,“ says Diehl. First though, they had to prove beyond all doubt that the concept of topological order can be transferred to a dissipative context at all. “We were able to tick off all points on the topological checklist and show that its prerequisites are also valid in a system with dissipative dynamics.” The physicists have published the mathematical proof of this new approach in the journal Nature Physics.
Publication: Topology by Dissipation in Atomic Quantum Wires. S. Diehl, E. Rico, M. A. Baranov, P. Zoller. Nature Physics. 2. Oktober 2011 DOI: 10.1038/nphys2106 http://dx.doi.org/10.1038/nphys2106Rückfragehinweis:
Dr. Christian Flatz | Universität Innsbruck
First evidence on the source of extragalactic particles
13.07.2018 | Technische Universität München
Simpler interferometer can fine tune even the quickest pulses of light
12.07.2018 | University of Rochester
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences