Quasiparticles can be used to explain physical phenomena in solid bodies even though they are not actual physical particles.
Physicists in Innsbruck have now realized quasiparticles in a quantum system and observed quantum mechanical entanglement propagation in a many-body system. The researchers have published their work in Nature.
Christian Roos’ research team at the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Sciences in Innsbruck has established a new experimental platform for investigating quantum phenomena: In a string of trapped ultracold ions they can precisely initialise, control and measure the states and properties of quasiparticle excitations in a many-body quantum system.
“Quasiparticles are a well-established concept in physics to describe the collective behaviour of particles in a simplified way,” says Christian Roos.
For the experiment the physicists used a one-dimensional ion-string consisting of between seven and fifteen calcium ions trapped in a vacuum chamber. Laser beams then manipulate the quantum state of the ions. “Each particle behaves like a little quantum magnet interacting with each other,” explains Petar Jurcevic, first author of this study. “The precise excitation of one of the particles also affects the other particles. The resulting collective behaviour of the system is called quasiparticles.”
These quasiparticles disperse to both sides of the excitation site on the ion-string, thereby, transporting quantum correlations. Excitation distribution has previously been observed in experiments with neutral atoms, where correlations between particles have also been shown.
“In our experiments we have been able to determine that these correlations are quantum correlations,” says Roos. “By measuring multi-particle correlations we have been able to detect and quantify quantum entanglement.” The physicists were, thus, the first to show entanglement propagation in a quantum system.
In contrast to previous experiments, the researchers in Innsbruck can tune the ion-ion interaction range in the system from effectively nearest-neighbour to infinite range. In each case, a new set of quasiparticles is created with unique dynamical properties.
New research with quasiparticles
“With this new scheme we can precisely manipulate the quasiparticles,” says an excited Philipp Hauke, one of the authors of this study. “It has taken us decades to come up with ways to precisely control and manipulate quantum particles. With this platform we can now do the same with quasiparticles and investigate phenomena that we haven’t been able to study experimentally.”
For example, it opens up new paths to study how quantum systems reach equilibrium, including the question of when thermalisation occurs, a process that so far has remained elusive. “Another big goal is to utilize quasiparticles for quantum information processing,” says Hauke.
In addition, this platform could also be used to study the role of transport processes in biological systems. At the moment Christian Roos’ research team is working on the idea to investigate interaction processes between two quasiparticles.
The study, now published in Nature, was jointly conducted by Peter Zoller’s theoretical research group and Rainer Blatt’s experimental research team at the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Sciences and the University of Innsbruck. The researchers are funded by the Austrian Science Fund, the European Commission, the European Research Council and the Federation of Austrian Industries Tyrol.
Publication: Quasiparticle engineering and entanglement propagation in a quantum many-body system. P. Jurcevic, B. P. Lanyon, P. Hauke, C. Hempel, P. Zoller, R. Blatt, and C. F. Roos. Nature 2014 DOI: 10.1038/nature13461
Institute for Quantum Optics and Quantum Information
Austrian Academy of Sciences
Phone: +43 512 507 4728
Phone: +43 512 507 32022
Mobile: +43 676 872532022
http://quantumoptics.at - Quantum Optics and Spectroscopy Group
Dr. Christian Flatz | Universität Innsbruck
Writing and deleting magnets with lasers
19.04.2018 | Helmholtz-Zentrum Dresden-Rossendorf
Ultrafast electron oscillation and dephasing monitored by attosecond light source
19.04.2018 | Yokohama National University
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
19.04.2018 | Materials Sciences
19.04.2018 | Physics and Astronomy
19.04.2018 | Physics and Astronomy